Dan Margulis Applied Color Theory

Photoshop LAB Color Arrives 
   Date: Mon, 25 Jul 2005 21:42:55 -0500
   From: "drhobbes"
Subject: Professional Photoshop

Dan,

Apparently your LAB book will be in the bookstores in the first week or two of August.  Now that this is out of the way, have you given any more thought to a new edition of Professional Photoshop?  Not to keep up with the constantly changing versions, but because your innovative and often controversial techniques using the old tools are quite a stimulus to continued experimentation.  It has crossed my mind that Adobe is attempting to keep up with your new ways of doing things with old tools by creating new tools to do much the same thing.

    On the other hand I realize that book-writing is not the most profitable pursuit in the world, its monetary worth being  inversely proportional to the amount of time and effort put into the writing the book in the first place.  But we can hope.  We can hope, can't we?

Howard Smith
___________________________________________________________________________

   Date: Tue, 26 Jul 2005 15:50:14 EDT
   From: Dan Margulis
Subject: Re: Professional Photoshop

I have always intended a new version of Professional Photoshop in 2006. I have just started to sketch out what will change and what will be added, and to assemble images that might be useful. But I want to wait and see how the LAB book is received before making final decisions.

Each edition of the book has had at least 60% new content. Stuff gets rotated out as it ages. The current edition's discussion of sharpening and its introduction to channel blending both date from 1998 and will certainly be upgraded. The sharpening chapter is still very sound so I expect I will simply add another chapter that discusses alternate methods and relates it to the use of Shadow/Highlight. The channel blending IMHO now needs to be redone from scratch.

As always, we will react to how workflows have changed between editions. So  there will certainly be discussions of Camera Raw and also of the implications of high-quality desktop printing, which was much less of a factor in 2002 when the last edition appeared than it is today.

Dan Margulis
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   Date: Tue, 26 Jul 2005 19:40:15 -0500
   From: "drhobbes"
Subject: Re: Professional Photoshop

Good! Good! Good!  That information brightened my day!  You might also consider publishing a collection of your EP articles, both for historical and educational reasons. Even your first book, Makeready, was well worth the search.  While of course you covered many of the same things in Professional Photoshop, the way you explained them in Makeready gave me a new way of looking at color correction that in turn led to development of some valuable new techniques that may never have occurred to me otherwise.

As for the new book on LAB, it will be a rousing success.  You can stop worrying about that now and start writing the new edition of Professional Photoshop.

You may be controversial, Dan, but we're sure glad you didn't step backward into that hole in Hawaii.

Howard Smith
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   Date: Fri, 12 Aug 2005 06:48:08 -0400
   From: Michael Cervantes
Subject: RE: Digest Number 1508

Nobody knows
how well a book on LAB will sell--it's uncharted territory. So the publisher
is guessing on how many to print, and guessing on how many to bring to
Photoshop World.

Coming from you, it is going to sell well. You should bring several boxes to Photoshop World.

Congratulations! I wish you a great success to your new book.

Best regards

Michael Cervantes
MC Design Studio
___________________________________________________________________________

   Date: Fri, 12 Aug 2005 13:33:25 +0200
   From: "Francisco Bernal"
Subject: Re: Digest Number 1508

Well, I want one, so at least, you know: count another.
:-)

/*--------------------------------------*/

Francisco Bernal Rosso

Luz-color-fotografia
Redacción y traducción
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   Date: Fri, 12 Aug 2005 14:20:04 EDT
   From: Dan Margulis
Subject: Publication Announcement: The Canyon Conundrum

It is a pleasure (and a relief) to announce that the official publication date of my new book on LAB was Monday, August 8. The title is Photoshop LAB Color: The Canyon Conundrum and other adventures in the most powerful colorspace (ISBN 0-321-35678-0). It's 384 pages in an 8x10 format. Price is $54.95. It's the first entirely new title I've published in eight years.

PDFs of the Table of Contents and Chapters 2 and 9 are posted at https://www.ledet.com/margulis/articles.html

The book is currently available at www.peachpit.com if you scroll through the authors list--it has not yet entered the search database. It should be available imminently at amazon.com, and will be shown at Photoshop World in Boston.

Handled with care, LAB maneuvers are extraordinarily powerful, often achieving effects that are not even possible AFAIK in other colorspaces. LAB is not, however, particularly user-friendly. I set out to write something that would be at least somewhat accessible to non-advanced users, while at the same time catering to professional-level retouchers and color specialists.

Therefore, each of the first six chapters is cut in half. The first halves are quite gentle IMHO. All commands are spelled out. The basics of an LAB workflow are developed. While there is some general discussion of under what circumstances you would want to use LAB or to avoid it, in these first halves I simply state that certain LAB methods work better than their RGB equivalents and leave it at that. The idea is to offer something that will give the inexperienced user striking results immediately, and a sharp improvement in color quality.

In the second halves (and in the final ten chapters of the book) the discussion gets more technical and there are many comparisons showing when LAB works better (or worse) than other alternatives.

Some top experts have seen drafts and offered mildly positive comments. David Biedny, the principal author of Photoshop Channel Chops and one of the great retouching authorities, contributed a foreword in which he called the book "the most deeply advanced, inspiring, insightful, maddening, awesome, demanding, and illuminating educational effort--in any media format--ever created for Photoshop."

Scott Kelby, who sells more books on Photoshop than anybody else, also had a read. His comment:  "This book is going to radically change how we all do color correction from this point on. Anyone not using the techniques Dan unveils in this book will soon be a digital dinosaur. It's that revolutionary."

More down-to-earth feedback came from a dedicated group of seven beta readers selected from this list, a group of very diverse backgrounds and skill levels. They caught a slew of unclear areas and offered many useful suggestions. If you like the book, you owe thanks, as I do, to Les De Moss, Andre Dumas, Bruce Fellman, Timo Kirves, Katia Lazarova, Clarence Maslowski, and Clyde McConnell.

Also, I'd like to thank the many list members who offered images for inclusion. Particularly, I'd like to thank those who, after discussing what I was after, were kind enough to send me a selection of *several* images. They are David Barr, Jim Bean, Michael Benford, Hunter Clarkson, Mike Demyan, Fred Drury, Jason Hadlock, Mark Laurie, David Leaser, Mike Russell, Marty Stock, Lee Varis, and Michael Vlietstra. I was looking for pictures that would best illustrate the potential of LAB, and it was critical that there be a good variety to choose from. Therefore, not every one of these people is represented in the book. However, each one of them made a significant contribution just by presenting alternatives, and the book is better because of them.

Here's a rundown of the contents.

1. THE CANYON CONUNDRUM
The basic LAB correction method is explained through a series of images of canyons.

2. LAB BY THE NUMBERS
How LAB is structured, what the numbers mean, how they interrelate with one another to create colors, and how they relate to the human visual system.

3. VARY THE COLOR, VARY THE RECIPE
The basic recipe of Chapter 1--an overall color enhancement--can be approximated in RGB, although the results will not be as good. When the A and B curves run at different angles, though, the result is unique to LAB.

4. IT'S ALL ABOUT THE CENTER POINT
Using LAB to eliminate color casts.

5. SHARPEN THE L, BLUR THE AB
LAB often, but not always, has a significant sharpening advantage over RGB, even when the RGB sharpening is done in Luminosity mode. When an image needs to be blurred, LAB is much better than RGB/Color mode. This chapter explains not just how but why, covering a lot of ground that is not well understood.

6. ENTERING THE FOREST: MYTHS & DANGERS.
Some avoid the use of LAB based on myths, which are debunked here. On the other hand, certain features of LAB are in fact rather dangerous if the user is not careful.

7. SUMMING UP: LAB AND THE WORKFLOW
The first half comes to a close with a discussion of when and why to use LAB, a question to which different users will come up with different answers. Only those who are extremely pressed for time would want an all-LAB workflow. Everyone else needs a disciplined approach to when to use it.

8. THE IMAGINARY COLOR, THE IMPOSSIBLE RETOUCH
LAB permits us to designate (at least theoretically) colors that could not possibly exist, such as a brilliantly red black. Doing so doesn't sound particularly intelligent, but using imaginary colors can be an extraordinarily powerful retouching tool.

9. THE LAB ADVANTAGE IN SELECTIONS AND MASKING
The best masks usually use a single channel as a base, but few people think of using the A or B for that purpose. In fact, those channels can make selections appear out of thin air--and in one spectacular example, they make a selection *of* thin air.

10. THE PRODUCT IS RED BUT THE CLIENT WANTS GREEN
The most effective way of making major color changes away from the art, as when the photograph portrays a product in one color but the client specifies not just another color but gives a PMS number to match.

11. THE BEST RETOUCHING SPACE
David Biedny, who is one of the world's most skilled retouchers, calls this chapter "nothing short of astounding."

12. COMMAND, CLICK, CONTROL
A chapter on advanced LAB curving that was one of the favorites of the beta readers.

13. THE UNIVERSAL INTERCHANGE STANDARD
We take a break from Photoshop technique to discuss LAB's role in the exchange of documents from one colorspace to another, and also see how the difficulties of setting up a conversion of out LAB suggest solutions for other kinds of color-matching issues, such as making CMYK matches to Pantone colors.

14. ONCE FOR COLOR, ONCE FOR CONTRAST
Four examples, one each of curves and of blends in Luminosity and Color modes. When should they be done in LAB, and when in RGB?

15. BLENDING WITH THE A AND B
The most difficult chapter of all considers blending the A and B channels into each other and/or the L for gains in contrast and color intensity.

16. A FACE IS LIKE A CANYON
We end the adventure with an easy, yet spectacular recipe for improving the believability of face shots, illlustrated step-by-step with five individuals of various ages and ethnicities.

This book took a lot more effort than I really would have liked. Unlike Professional Photoshop, every chapter was completely new. Also, because so many of the techniques are bleeding-edge, they haven't been studied much, and I was learning as I went along. I am pleased with the results and think that almost everyone will find some powerful new tools and significant improvements for their own workflow.

As previously announced, I plan a new edition of Professional Photoshop in 2006. It will certainly vary considerably from the current edition, but a lot will depend on what the reaction to this LAB book is.

Dan Margulis
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   Date: Fri, 12 Aug 2005 15:04:23 -0700
   From: Glenn Huish
Subject: Re: Re:_Boston_Photoshop_Conference, LAB book?

Dan Margulis wrote:

Nobody knows
how well a book on LAB will sell--it's uncharted territory. So the publisher
is guessing on how many to print, and guessing on how many to bring to
Photoshop World.

heh. this is so true, i never really thought about it.

well, i'm already good for one, now if amazon just gets it out the door...

Glenn A. Huish

  Chief Technical Officer
  Bel Aire Displays
  5710 Hollis St.
  Emeryville, CA 94608
  510.654.0964 x27

http://www.belairedisplays.com
___________________________________________________________________________

   Date: Sat, 13 Aug 2005 10:41:36 -0400
   From: Patrick Chuprina
Subject: Re: Publication Announcement: The Canyon Conundrum

Congratulations!  Now to wait the the 4 to 6 weeks Amazon.ca says it takes to ship.  I'm really looking forward to this.

Patrick Chuprina
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   Date: Sun, 14 Aug 2005 00:56:36 -0700 (PDT)
   From: dimitrij saherl
Subject: Re: Publication Announcement: The Canyon Conundrum

Best wishes with the new book. It¨s a brilliant. /based on chapter 2 and 9, articles in Photoshop user./
 
Regards, dimitrij
 
dimitrij saherl
www.av-studio.si
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   Date: Mon, 29 Aug 2005 18:10:13 -0000
   From: "hfdomke"
Subject: Eighteen Questions about Dan's new LAB book

Questions from Henry Domke on Dan Margulis's book: "Photoshop LAB Color, The Canyon Conundrum and Other Adventures in the Most Powerful Colorspace"

The first 8 questions are my main questions. Questions 9 through 18 are more minor questions and observations.

1. Why be so opposed to selections? The entire book seemed excessively focused on global corrections.

2. How does one manipulate the red-cyan axis in LAB? How is it buried in the AB channels?

3. Does Adobe Capture RAW run on LAB? It too has no control for the red-cyan axis. Isn't the temperature slider really a "B" slider (yellow-blue) and the tint slider the "A" slider (magenta-green)?

4. Chapter Six: "In the last three years, around a dozen people, including me, have made serious efforts to find anything to support the proposition that 16-bit editing might be better under any circumstances. … nobody has found any quality gain at all." This is certainly provocative and counter-intuitive. What do other respected authors have to say about this topic? Say the authors of Real World Photoshop?

5. If we enhance color variability somewhere by increasing the slope of the curve does that mean we loose it somewhere else? This is true with contrast adjustments using curves in other color spaces.

6. Why on earth doesn't Dan use layer masks for some of his corrections? With today's fast processors and cheap memory, layer masks are very fast and can be revised. One thing with his techniques is that you had better get it perfect the first time or go back and start from the beginning. What about the mantra of many Photoshop gurus who say: never do destructive editing, always leave yourself an out. His methods almost always are irreversible. Comment?

"Too many people use selections as crutches. The better you get at image manipulation, the less you make them." P. 182 and his comment on p. 189 "Creating a selection is for those who are certain they know what they want. Making a mask is for those who want room to experiment."   Your bias here is not my experience.  I have been using Photoshop since version one. For years I have used it every day on thousands of images. I have found that specialized selections (layer masks that I paint on with a Wacom tablet) provide fast and realistic manipulation. It allows me to change opacity later, or even go back and change the settings on the Adjustment layers. The painting in layer masks is very intuitive. I use Actions to create masks such as: Contrast, Darken, Lighten and Boost Saturation.  I just apply them where I want. Have you ever give a serious look at that workflow? What is wrong with experimenting (as you say) anyway?

7. On page 106:  Photoshop's Camera RAW plug-in has a setting to control it but "working the AB is a more elegant and effective solution". Is that still true with Photoshop CS2? Isn't "Luminance smoothing" simply blurring the L channel and Color Noise Reduction simply blurring the AB channels? Is this another example of LAB being behind the scenes in Capture RAW plugin?

8. On page 114 Dan writes "We haven't used selections or masks yet in this book. They'll rear their ugly heads at the end of Chapter 7. Most people overuse them." What makes you say that? You seem almost pathologically averse to considering using Adjustment layers which have associated masks as fully explained in Real World Photoshop CS. Why?

9. Why do the A and B channels range from 127 to minus128? Why aren't they the same number?

10. Most of the illustrations in the book are remarkably clear and demonstrate what is being discussed. However, I think Figure 8.13 is a poor example. To my eye the line separating the blue sky and the blue mountains is too pronounced and fake looking

11. In Chapter 6 he writes: "Standard deviation can also be part of image analysis. Like the histogram I consider it worthless as an aide to image manipulation. Neither can tell us about the visual quality of an image as accurately as our own eyes do". Isn't this a bit harsh? "Worthless"? Not to me. Many Photoshop users find looking at histograms critical. Have we clipped the image? Do we have adequate tonal range?

12. Most of the book seems to be a pep talk about all the great things about LAB. He doesn't spend much time talking about the downsides of LAB. For example in LAB the following does not work:
1. Adjustment Layers: Selective Color, Channel Mixer
2. Filters:  Several (although USM and the blur filters do work).
      3. 32 bit color

13. You caution about using LAB in any other program than Photoshop. I noticed that in Adobe's Creative Suite Professional CS2 that at least two programs could work with LAB. InDesign and Acrobat 7 Professional. Would they not print properly?

14. There must be some relation to saturation and color variability, yes? Steepening the curves in AB clearly have increased saturation as one of their attributes, yes? You can't increase color variability without increasing saturation, can you?

15. Dan states in Chapter 5: "Deciding whether an image has a cast is probably the most difficult task in color correction."  If this is true, then should professional photographers make it a rule to always shoot a grey card? How much would that help?

16. Wouldn't it better to do all LAB curves on an Adjustment layer? For one thing you can only do one curve per channel in Lab, they don't all pop down like in RGB. Furthermore, you can very opacity of the layer if you wish, after the fact.

17. Chapter 5: "Focus is a question of luminosity variation, not color. Noise is color only, with little change in luminosity". What about film grain, that has luminosity variation also, yes? You must just be referring to digital capture only.

18. What is your take on the two-step sharpening process advocated by the folks at PK Sharpener Pro? They propose applying a "Capture Sharpening" which is applied early on in the sharpening process.  It's aim is to restore sharpness lost during the capture process. This book (and common sense) advocates that sharpening occur near the end of your Photoshop work. www.pixelgenius.com

Thanks,
Henry F. Domke
Henry Domke Fine Art
www.henrydomke.com
____________________________________________________________________________

   Date: Mon, 29 Aug 2005 15:49:47 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 8/29/05 12:10 PM, "hfdomke"  wrote:

3.      Does Adobe Capture RAW run on LAB? It too has no control for the
red-cyan axis.  Isn't the temperature slider really a "B" slider
(yellow-blue) and the tint slider the "A" slider (magenta-green)?

No, not at all. The RAW file is a Grayscale data file. ACR converts this (demosicing) into a linear encoded (gamma 1.0) ProPhoto RGB color space and from there, into one of it1s four supported RGB working spaces.

7.      On page 106:  Photoshop's Camera RAW plug-in has a setting to
control it but "working the AB is a more elegant and effective solution". Is
that still true with Photoshop CS2? Isn't "Luminance smoothing" simply blurring the L
channel and Color Noise Reduction simply blurring the AB channels? Is this another example of LAB being behind the scenes in Capture RAW plugin?

No, ACR doesn1t touch LAB in any way although I can ask Thomas Knoll if his two proprietary camera profiles make a call to CIEXYZ (it wouldn1t be LAB).

18.      What is your take on the two-step sharpening process advocated by
the folks at PK Sharpener Pro?

We actually propose a three step process, the middle is creative sharpening which is totally optional. The workflow is discussed here:

http://www.creativepro.com/story/feature/20357.html

Andrew Rodney
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   Date: Tue, 30 Aug 2005 12:06:18 -0400
   From: Lee Clawson
Subject: Re: Eighteen  Questions about Dan's new LAB book

on 8/29/05 2:10 PM, hfdomke awrote:

Henry,

With all due respect to Dan I'll give you some idea how I see this stuff......

I'll preface my comments by saying that a lot of your questions seem to be about workflow, that is, which workflow works best in a given situation. In our studio there's more than one, changing with the needs of the work.

Lee  
________________________

1.    Why be so opposed to selections? The entire book seemed excessively
focused on global corrections.

I don't like making them either. They're tedious and can take too long.

5.    If we enhance color variability somewhere by increasing the slope of the
curve does that mean we loose it somewhere else? This is true with contrast
adjustments using curves in other color spaces.

I assume this happens, that is, "we loose it somewhere else". What's lost usually doesn't bother me in comparison to what's gained.

6.    Why on earth doesn't Dan use layer masks for some of his corrections?
.......methods almost always are irreversible. Comment?

"Too many people use selections as crutches..........I have found that
specialized selections (layer masks that I paint on with a Wacom tablet)
provide fast and realistic manipulation........

Have you ever give a serious look at that workflow? What is wrong with experimenting (as you say) anyway? I have no problem with your work flow. I don't work like Dan does either. I rarely use layer masks. I think it has a lot to due with how or when you learned color correction. Please keep in mind this has been done without a computer and it's inherent reversibility for a long, long time. (Add the same comments to question #8 too)

10.    Most of the illustrations in the book are remarkably clear and
demonstrate what is being discussed. However, I think Figure 8.13 is a poor
example. To my eye the line separating the blue sky and the blue mountains
is too pronounced and fake looking

One image is off, egads!!! -- You should spend a day in our studio.
 
11.    "Standard deviation can also be part of image analysis...the histogram
I consider it worthless ...... Isn't this a bit harsh? "Worthless"?
Not to me. ....Have we clipped the image? Do we have adequate tonal range?

Haven't used the histogram either. I think it's useful for calibration tasks but having the answers it provides doesn't help me when looking at what I want from an image.

13.    You caution about using LAB in any other program than
Photoshop.....Would they not print properly?

I don't know of a RIP that would do the on-the-fly conversions.
____________________________________________________________________________

   Date: Tue, 30 Aug 2005 12:06:15 -0600
   From: Andrew Rodney
Subject: Re: Eighteen  Questions about Dan's new LAB book

On 8/30/05 10:06 AM, "Lee Clawson"  wrote:

13.    You caution about using LAB in any other program than
Photoshop.....Would they not print properly?
I don't know of a RIP that would do the on-the-fly conversions.

ImagePrint can.

Andrew Rodney
____________________________________________________________________________

   Date: Tue, 30 Aug 2005 12:58:13 -0600
   From: Andrew Rodney
Subject: Re: Eighteen  Questions about Dan's new LAB book

On 8/30/05 12:44 PM, "Henry Domke"  wrote:

I have always beenÊuncomfortable with the conceptÊof two (or three-step)
sharpening.ÊSharpening always alters the image by accentuating edge contrast.Ê

How else would you sharpen an image?

The sharpening is all layer based so unless and until you flatten, the underlying data is never affected. All the sharpening is done using complex masks on the actual pixel data. This is something that can1t be done globally and is ideally done in Photoshop. Masks allow the protection of areas that should not undergo sharpening. For example, smooth shadows which when sharpened would increase noise. A mask allows one to decide what edges get sharpened, where in the tonal scale, how smooth etc. You can do all this manually but then you need to know what values to plug in for the capture device (how much sharpening is needed to over come the digitizing process) and then how much for the output device. That secondary sharpening has to understand the first sharpening process or it1s too little or too much.

If one does this early on during image preparation, I fear that some
manipulation, especially enlargement, will accentuate this sharpening
artifact.Ê
 
This is why output sharpening is done at output resolution since of course, this is resolution dependant. Capture sharpening is too but its VERY subtle and is only used to produce a good master for all additional sharpening. This is a lot like your RGB working space master in which you can apply any number of output profiles for the output needs.

Many of my prints are sold very large. For example I am preparing a 10x60 foot
mural today.

And output sharpening would be applied based on that exact size to the device you tell us you want to send the pixels to. That1s why you need different settings for halftone based on a linescreen versus an ink jet versus a contone printer. Size AND output device needs to be defined. If you decide you want to print at half that size, you go back to the original 3master2 with it1s capture sharpening, size and then sharpen for a specific output device at that specific size. The capture sharpening will be 3correct2 for either size since the big sharpening moves are all output.

Have you done A-B comparisons with images greatly enlarged (20 x 30 inches and
much larger) to see if two-step sharpening is actually better then sharpening
near the end?Ê

Yes! And so can you with the demo which is fully functional for 7 days.

By-the-way, I own PK Sharpener Pro and do use it some, but I never do the
capture sharpen

You should because the output sharpening is assuming the file has undergone capture sharpening and was designed for that in mind. Now you don't have to but that's how the workflow was designed. Why not do that (it will be on a layer) apply output sharpening and print with the capture layer on and off.

Andrew Rodney
____________________________________________________________________________

   Date: Tue, 30 Aug 2005 13:44:51 -0500
   From: Henry Domke
Subject: Re: Eighteen  Questions about Dan's new LAB book

Andrew,

First, I should tell you that your new book "Color Management for Photographers" arrived today from Amazon. I am really looking forward to reading it.

You responded to my question:
We actually propose a three step process, the middle is creative  
sharpening which is totally optional.

I have always been uncomfortable with the concept of two (or three-step) sharpening. Sharpening always alters the image by accentuating edge contrast. If one does this early on during image preparation, I fear that some manipulation, especially enlargement, will accentuate this sharpening artifact. Many of my prints are sold very large. For example I am preparing a 10x60 foot mural today.

I prefer to do all my image manipulation at my cameras native resolution(4992 x 3328 pixels with my Canon 1Ds Mk2) Since I sell prints of many sizes I prefer to do my sizing just before printing and it is after sizing the image that I typically do my once and only sharpening with USM.

Have you done A-B comparisons with images greatly enlarged (20 x 30 inches and much larger) to see if two-step sharpening is actually better then sharpening near the end? I fear that most of your users output to print publications and that the images are much smaller. My needs may be different.

By-the-way, I own PK Sharpener Pro and do use it some, but I never do the capture sharpen.

Talk to you soon,
Henry

Henry Domke Fine Art
www,henrydomke.com
____________________________________________________________________________

   Date: Tue, 30 Aug 2005 22:37:42 EDT
   From: Dan Margulis
Subject: Re: Eighteen Questions about Dan's new LAB book

Henry Domke writes,
 
1.  Â  Why be so opposed to selections? The entire book seemed
excessively focused on global corrections.

Chapter 9 is titled "The LAB Advantage in Selections and Masking". In subsequent chapters, particularly Chapters 11 and 16, there is extensive coverage of masking and of layer Blend If options, a sophisticated form of selection.
 
2.  Â  How does one manipulate the red-cyan axis in LAB? How is it buried
in the AB channels?
 
This is explained in the second half of Chapter 4. Red is defined as positive  A, positive B. Cyan is negative A, negative B.
 
3.  Â  Does Adobe Capture RAW run on LAB?
 
No.

4.  Â  Chapter Six: "In the last three years, around a dozen people, including me,
have made serious efforts to find anything to support the proposition that
16-bit editing might be better under any circumstances. ... nobody has found any quality
gain at all." This is certainly provocative and counter-intuitive. What do other respected
authors have to say about this topic? Say the authors of Real World Photoshop?
 
At present there is to my knowledge no person in the world claiming to possess any real-world color photograph, to which any series of real-world corrections were applied, where the results are any better when done in 16-bit than in 8-bit. Many people, on the other hand, have run tests in which absolutely massive corrections have been applied, far beyond anything that would ever be done in the real world, and there is no evidence at all of any advantage. New examples are shown, at high magnifications, in Chapter 6. At this point the evidence is overwhelming that there is no 16-bit advantage in dealing with color photographs. A few people argue otherwise, but it has now become a matter of religious belief, rather than reliance on demonstrations that they can't provide.

With respect to the author you mention, in a recent thread on the ColorSync list I repeatedly asked him whether he had ever personally run a test (or seen anyone else perform such a test) where the same exact corrections were applied in both 8- and 16-bit modes to a real-world color photograph, and compared the results. He repeatedly refused to answer.

5.  Â  If we enhance color variability somewhere by increasing the slope
of the curve does that mean we loose it somewhere else? This is true with contrast
adjustments using curves in other color spaces.
 
It is true in the L channel but not in the A and B, because a substantial area of each curve covers colors that are not in use. There are certain cases where one *wishes* to lose color variation but there is no need to do so.

6.  Â  Why on earth doesn't Dan use layer masks for some of his
corrections?

According to the index, there are discussions of layer masking on pages 176-178, 192-194, 206-208, 220, 223, 225. The very image that you complain about in item #10 below is prefaced by a lengthy discussion of how to make a layer mask, and the layer mask itself is shown as a separate graphic in Figure 8.11.

One thing with his techniques is that you had better get it perfect the
first time or go back and
start from the beginning. What about the mantra of many Photoshop
gurus who say: never
do destructive editing, always leave yourself an out. His methods
almost always are irreversible. Comment?
 
The book is not about how to use the history palette, or about when and how often to save intermediate backup files, or about how layers are appropriately used in Photoshop documents. It is about how LAB functions. We have to assume that each reader will use a workflow that is sufficiently flexible to meet his own objectives.
 
"Too many people use selections as crutches. The better you get
at image manipulation,
the less you make them." P. 182 and his comment on p. 189
"Creating a selection is for
those who are certain they know what they want. Making a mask is for
those who want
room to experiment."   Your bias here is not my experience.  
 
The chances are that your experience is based only on comparisons of your own images with your own images, whereas I've had the opportunity to watch people use the selection-first method in competition on the same image with others who don't. Remember, I've trained well over a thousand people intensively, meaning over periods of several days or more. Those people who use selections as a first rather than a last resort consistently achieve lower-quality results than their colleagues, and they invariably state afterwards that they realize they should not have been selecting as much as they had.

I also have the opportunity to observe advanced classes, where the average student is approximately as good as I am in color correction, and where they have had months if not years to apply and experiment with what they have learned in the first class. It is absolutely clear that as people become more skilled in color correction they make fewer selections.

7.  Â  On page 106:  Photoshop's Camera RAW plug-in has a setting to
control it but "working the AB is a more elegant and effective solution". Is
that still true with Photoshop CS2? Isn't "Luminance smoothing" simply blurring the L
channel and Color Noise Reduction simply blurring the AB channels?

No, it's doing the arithmetic in RGB and then attempting to revert to luminosity or color afterward. As discussed in Chapter 5, "Sharpen the L, Blur the AB," there is a decisive advantage to doing color blurs in LAB rather than RGB/Color mode. Plus, the blurring tools in Camera Raw are much cruder than those found in Photoshop proper.
 
8.  Â  On page 114 Dan writes "We haven't used selections or
masks yet in this book. They'll rear their ugly heads at the end of Chapter 7. Most people overuse them." What makes you say that?
 
See #6 above.

You seem almost pathologically averse to considering using
Adjustment layers.
 
According to the book's index, adjustment layers are discussed, always positively AFAIK, on pages 115, 152, 193-195, 206, 222, 243, 298, 326. Many of the screen captures showing layer structure in this book indicate that there were adjustment layers in the document.
 
9.  Â  Why do the A and B channels range from 127 to minus 128? Why
aren't they the same number?
 
Because, as explained in the box on Page 98, a channel must have exactly 256 discrete values, but zero is a possible value, leaving an odd number to be divided in half.

10.  Â  Most of the illustrations in the book are remarkably clear and
demonstrate what is being discussed. However, I think Figure 8.13 is a poor example. To
my eye the line separating the blue sky and the blue mountains is too pronounced and
fake looking
 
As indicated in the text, in real life a retoucher would likely substitute a real sky from another picture rather than trying to create one using imaginary colors in LAB. In any case the transition is less pronounced than in the original.
 
11.  Â  In Chapter 6 he writes: "Standard deviation can also be part
of image analysis. Like the histogram I consider it worthless as an aide to image
manipulation. Neither can tell us about the visual quality of an image as accurately as our own eyes do". Isn't this a bit harsh?

No, it's probably too generous. Histograms can be useful in after-the-fact analysis of an effect, as, for example, in showing why sharpening in LAB sometimes works better than in RGB/Luminosity. They can be useful in image capture, where the objective is not to make a perfect image but to make sure that nothing is lost. In color correction, they are actually worse than useless when people rely on them rather than their own eyes. The question is not whether anything is clipped but whether anything SIGNIFICANT is clipped. Histograms can't answer this question.
 
12.  Â  Most of the book seems to be a pep talk about all the great
things about LAB. He doesn't spend much time talking about the downsides of LAB.
 
The title of the book, "The Canyon Conundrum", refers to the question of why LAB does so well on certain categories of image (e.g. canyons) and not so well on others. The purpose of Chapter 6, "Entering the Forest, Myths and Dangers" is to explore not just misconceptions about LAB, but also when to avoid using it. Most of Chapter 7 is devoted to discussing what types of operation should be done in LAB and what types at other times in the workflow. The entirety of Chapter 14 discusses how to identify pictures that are better handled in RGB than in LAB, and vice versa.
 
13.  Â  You caution about using LAB in any other program than Photoshop.
I noticed that in Adobe's Creative Suite Professional CS2 that at least two
programs could work with LAB.
InDesign and Acrobat 7 Professional. Would they not print properly?
 
Not reliably, as explained in Chapter 6.
 
14.  Â  There must be some relation to saturation and color variability,
yes? Steepening the curves in AB clearly have increased saturation as one of their
attributes, yes? You can't increase color variability without increasing saturation, can you?

Yes. In LAB, often the variation is created by saturating one color and desaturating a highly similar one, as described in Chapter 12.
 
15. Dan states in Chapter 5: "Deciding whether an image has a
cast is probably the most difficult task in color correction."Â  If this is true, then
should professional photographers make it a rule to always shoot a grey card? How much would that help?

It would be useful in many cases.
 
16.  Â  Wouldn't it better to do all LAB curves on an Adjustment
layer?
 
No, and there's nothing LAB-specific about this topic. Some people need the flexibility of adjustment layers and others don't. Many if not most users intend to output once only, and never correct again. It's pointless for them to waste time with extra documents, no matter what colorspace they work in.
 
17.  Â  Chapter 5: "Focus is a question of luminosity variation, not
color. Noise is color only, with little change in luminosity". What about film grain, that
has luminosity variation also, yes? You must just be referring to digital capture only.
 
Amazing how the omission of only one word can change the entire meaning of a phrase. The actual quotation, with the omitted word capitalized, reads as follows: "Focus is a question of luminosity variation, not color. Noise is OFTEN color only, with little change in luminosity." The word "often" does not mean "always". It does not mean "almost always". It does not mean "most of the time", or "usually".
 
18.  Â  What is your take on the two-step sharpening process advocated by
the folks at PK Sharpener Pro?
 
I am not familiar with it, sorry.

Dan Margulis
____________________________________________________________________________

Date: Tue, 30 Aug 2005 22:37:58 EDT
   From: Dan Margulis
Subject: You're Number One

For those following such things, the publisher interrupted my vacation today with the news that as of this morning the LAB book was the #1 selling amazon.com title in the entire computer/internet field. This is totally surprising since the official rollout of the book isn't until Photoshop World next week. Its ranking is about #50 in all books that amazon.com sells.

I would like to again thank the list members who encouraged this project from the beginning. A lot of people had serious doubts that people would buy a book on such a limited topic. If it hadn't been for the feedback from the list, I wouldn't have begun it.

Dan Margulis
____________________________________________________________________________

   Date: Tue, 30 Aug 2005 21:36:07 -0700
   From: Christopher Zsarnay
Subject: Re: You're Number One

Dan,

Congratulations on the sale of the book.!!  I just received my copy today and I'm looking forward to diving in.

Thanks for writing it.

Chris

Christopher Zsarnay
Z Studios Photography
805-644-5554
http://www.zstudios.com
AIM & IChat:  czsarnay
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 07:24:24 -0500
   From: "Henry Segalini"
Subject: Re: You're Number One

Congratulations.

This list has been very helpful and informative to me.

I'm glad you got something from it as well.

Henry Segalini
Universal Printing
St. Louis  MO
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 09:32:35 +0100
   From: Martin Bailey
Subject: Re: Eighteen  Questions about Dan's new LAB book

At 19:06 30/08/2005, Andrew Rodney wrote:

ImagePrint can.

If the Lab ends up in a PDF file, then any RIP that claims to fully support PDF should be able to. If it's in a PostScript or EPS file then it's actually encoded as a normal color space array (CSA), so any PostScript Level 2 or later RIP should handle it.

Of course, the quality of the conversions probably varies between implementations.

Thanks

Martin Bailey

-------------------------------------------------------------
  Senior Technical Consultant                +44 1223 873800
  Global Graphics Software        http://www.globalgraphics.com
  Developers of Harlequin & Jaws RIPs and Jaws PDF Technology
-------------------------------------------------------------
If my views didn't usually coincide with those of my employer
  I wouldn't want to work here, but I am not a spokesman for
                 Global Graphics Software
         and the buck stops with me for what I say.
-------------------------------------------------------------
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 07:10:54 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 8/30/05 8:37 PM, "Dan Margulis"  wrote:

With respect to the author you mention, in a recent thread on the ColorSync
list I repeatedly asked him whether he had ever personally run a test (or seen
anyone else perform such a test) where the same exact corrections were applied
in both 8- and 16-bit modes to a real-world color photograph, and compared
the results. He repeatedly refused to answer.

He has an example on page 24 of Real World Camera RAW.

Andrew Rodney
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 12:40:25 -0000
   From: "hfdomke"
Subject: Response to Margulis's answers my 18 Questions about LAB book

Dan's words are in quotes.

2. How does one manipulate the red-cyan axis in LAB? How is it buried in the AB channels?

"This is explained in the second half of Chapter 4. Red is
defined as positive A, positive B. Cyan is negative A, negative B."

But is it possible to manipulate and increase color variability of Red-Cyan like we can Green-Magenta or Blue-Yellow by steep curves in the A & B channels? Are there any simple moves we can make to affect Red-Cyan?

4. "At this point the evidence is overwhelming that there is no
16-bit advantage in dealing with color photographs. A few people argue otherwise, but it has now
become a matter of religious belief, rather than reliance on demonstrations that they
can't provide".

This is a very important issue for all of us that use Photoshop. Many of us now keep our multi-layered files as 16-bit until we are ready to print. I have 10,000 files like this and I don't want to double my storage requirements and slow my processing time by using 16-bit unless there is clearly a benefit. We need to get a definitive answer.

I am going to start an active web and email campaign to see if we can get the experts to agree on this. I encourage others to join me in helping to answer this question decisively. A question with a look to the future: I have heard some speculation that at some point printers might support 16-bit files directly. Would that be a case where there might be some advantage?

6. Why on earth doesn't Dan use layer masks for some of his corrections?

"According to the index, there are discussions of layer masking
on pages …"

However, I don't think there is one illustration in this 366-page book showing a layer mask. Instead, he repeatedly shows "Blend If" sliders.  To my inexperienced way of thinking, Blend-If is a crippled version of a layer mask. Layer masks on Adjustment Layers allow you to use gradients, work with variably edged selections, change opacity and alter blending modes.  If you save the layer with the image, you can go back and tweak it later if the client wants a change.

"The book is not about how to use the history palette, or about
when and how often to save intermediate backup files, or about how layers are appropriately
used in Photoshop documents. It is about how LAB functions."

I never referred to the history palette or intermediate backup files. However, if one creates their LAB curves on an adjustment layer, it leaves room to revisit the file for adjustments much more easily. As my father always said "Keep your options open."

18. What is your take on the two-step sharpening process advocated by the folks at PK Sharpener Pro?
"I am not familiar with it, sorry."

What kind of answer is that? You have written and taught extensively on the critical issue of sharpening. I know because I have read the different editions of your still outstanding "Professional Photoshop."  On page 78 of "Professional Photoshop 6" you write " Applying a major adjustment to an image after USM can exaggerate the artifacts of sharpening."

Do you not have an opinion on two (or three) step sharpening? What do you think of the concept of capture sharpening in addition to output sharpening? I would guess, based on your writings that you would argue against it theoretically and would call for examples to prove it in the "real world."

Lastly, thanks for writing another thought provoking book. Your thinking and writing style are outstanding. It is fun to disagree with you.
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 10:50:31 +0200
   From: Kim Müller
Subject: Re: You're Number One

Congratulation. Still waiting for my copy.

Have you considered making an in depth-book on cmyk and prep for print? The (out of print) "MakeReady" was maybe such a book? What about updating it?
Thanks.

Kim Müller
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 07:56:44 -0600
   From: Andrew Rodney
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book

On 8/31/05 6:40 AM, "hfdomke"  wrote:

I am going to start an active web and email campaign to see if we can
get the experts to
agree on this. I encourage others to join me in helping to answer
this question decisively.
A question with a look to the future: I have heard some speculation
that at some point
printers might support 16-bit files directly. Would that be a case
where there might be
some advantage?

Some already do. If you have an Epson driven by the ImagePrint RIP, you can use and in some cases see the benefits since it1s used within it1s proprietary dither.

As for definitive answers, good luck. There are so many criteria that it1s nearly impossible to get multiple parties to agree on testing. We also have no idea what output devices will come onto the scene in a year, let alone 5 or what RIP or driver might utilize the additional data so if I were you, I1d keep those thousands of files in high bit. Storage is cheap, all things being equal. You1ve got the data, so keep it intact.

Andrew Rodney
\____________________________________________________________________________

   Date: Wed, 31 Aug 2005 09:23:43 -0700 (PDT)
   From: C Sutherland
Subject: Re: You're Number One

Dan,

I've had the book for about 2 weeks- ordered from Peach Pit as soon as it was announced. It is very, very useful and would sure recommend it to the list. Not a quick read but didn't expect one. Congratulations on the success.

Craig Sutherland
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 15:41:48 -0400
   From: Iliah Borg
Subject: Re: You're Number One

This is the response we got from one of the readers and followers on dpreview.com :)

"Ignore this ... to your own peril....

I have been finding new ways to PP my shots for years now....this by far absolutly BLOWS AWAY any PP techniques I have learned to date.

The reason its so diffrent is it uses Lab Colorspace which is EXTREEMLY diffrent thean CMYK or RGB...and your photos respond diffrently...VERY diffrently.

This book is manditory reading to ANYONE who wants fast PP with no hassles."

Best regards,
ib
____________________________________________________________________________

   Date: Wed, 31 Aug 2005 21:17:35 -0400
   From: "Gene Palmiter"
Subject: Re: You're Number One

Congrats...I will order mine tomorrow. I would ask that for future updates you make it clear about the year it came out...I got the wrong version of Professional Photoshop from Amazon because it wasn't clear which version was newest. Of course I can see why publishers might not want to be clear on that...they sold me a book that I wasn't looking to buy.

Thanks,
Gene Palmiter
(visit my photo gallery at http: //palmiter.dotphoto.com)
freebridge design group
www.route611.com & Route 611 Magazine
____________________________________________________________________________

   Date: Thu, 1 Sep 2005 08:39:48 -0700
   From: mac townsend
Subject: Re: You're Number One

Unless you already have it, the previous edition (which does not focus on LAB beyond a single chapter) should be a good companion / prerequisite for the LAB book.

Mac Townsend
Adcom Graphics Digital Imaging
Fairfield, California
____________________________________________________________________________

   Date: Thu, 1 Sep 2005 12:19:52 -0400
   From: John Ruttenberg
Subject: Re: Eighteen Questions about Dan's new LAB book

Dan Margulis:

At present there is to my knowledge no person in the world claiming to
possess any real-world color photograph, to which any series of real-world
corrections were applied, where the results are any better when done in
16-bit than in 8-bit. Many people, on the other hand, have run tests in
which absolutely massive corrections have been applied, far beyond anything
that would ever be done in the real world, and there is no evidence at all
of any advantage. New examples are shown, at high magnifications, in Chapter
6. At this point the evidence is overwhelming that there is no 16-bit
advantage in dealing with color photographs. A few people argue otherwise,
but it has now become a matter of religious belief, rather than reliance on
demonstrations that they can't provide.

Without meaning to open this can of worms once again there is one particular correction for which 16 bit input makes a lot of sense, at least in theory: highlight/shadow.  When starting with raw input when I know that highlight/shadow will be used to recover either shadows of highlights, I move the shadow and exposure sliders so that no clipping occurs and convert to 16 bit format.  When stretching for dynamic range, doesn't it make sense to have deeper pixel data?  I can't say that I have tested this carefully, so I may be wrong.  But there seems to be no harm in this particular piece of workflow and it might even help sometimes.
____________________________________________________________________________

   Date: Thu, 01 Sep 2005 10:35:40 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

I think it1s important to point out that dynamic range and bit depth are two totally separate issues/specs.

Like you, when I1m working with high bit RAW data, I bring this in a bit on the flat side. I know I can move either end closer to 3clipping2 without introducing any banding. I also know that some sharpening as well as conversion to an output space can move those points so I want to start out with some headroom. You could do the same in 8-bit but you1ve got far fewer steps from say 250 to 255 to set perhaps a specular  highlight. In 8-bit, I1ve got 5 steps. In high bit (which could be 10/12/14 or 16-bit depending on the capture device), I have a lot more. So I1m not concerned about setting the ends of the tone scale at the RAW conversion or scanning stage. I'll work on the master which is a tad flat, convert (or view a soft proof with the output profile), output sharpen and see where things lie.

Highlight recovery is different. At least when using Adobe Camera RAW. It can actually recover lost highlight if you have one color channel with data. That is, if you1ve blown out (clipped) two color channels, ACR can reconstruct them from one remaining channel that has data. As far as I know, this is a unique feature of Adobe Camera RAW and a pretty useful feature of linear encoded RAW data.

Andrew Rodney
____________________________________________________________________________

   Date: Thu, 1 Sep 2005 13:06:06 -0400
   From: Henry
Subject: Re: Eighteen Questions about Dan's new LAB book

Data is not the same thing as printed results.

Before committing to a dogma that insists on always using 16 bit, it should be for real good reasons that I'm sure 16 bit fans will offer in reply.

One can put a high performance racing carburetor on a lawn mower, but it won't do a better job.  It will, however, cost more.

Henry Davis
____________________________________________________________________________


   Date: Thu, 1 Sep 2005 10:18:38 -0700
   From: Richard Chang
Subject: 16 bit printing

A recently posted question wondered:

 A question with a look to the future: I have heard some speculation
 that at some point  printers might support 16-bit files directly. Would that be a case
 where there might be some advantage?

The bigger question in my mind is how many bits can be seen (or measured, for that matter) on a reflective rendering?

We can use a traditional reflection densitometer to derive a D log value for any paper and inks combo.  Bits can be mathmatically related to the D log values.  Measurements made by MegaVision back in the late 80's when they were considering the making of the first Tessera digital capture device, returned 6.5 bits for a high performing sheet fed press.

It might be interesting to measure some reflective targets to see how they perform with today's technically advantaged rendering methods. Yes, we can send 16 bit files to some devices, but can we really see a difference between an 8 bit and a 16 bit file on the print?   Just because the driver will accept the 16 bit file, doesn't necessarily mean that the viewer can see it.  It could however, have marketing advantages to the folks who are selling the technology.

If we consider how many individually seperable tones we can see reflected from a print, common sense should tells us we should send a prudent amount more, to make sure we've sent enough.  Sending a 16 bit file sounds a lot like printing in 2880, versus 1440.  Does this mean that we're going to have to use the 2880 setting to see the 16 bits?

Richard Chang
____________________________________________________________________________

   Date: Thu, 1 Sep 2005 17:40:46 EDT
   From: Dan Margulis
Subject: Re: You're Number One

Kim writes,

Have you considered making an in depth-book on cmyk and prep for print?

My book Professional Photoshop has a fair amount of such material.

The (out of print) "MakeReady" was maybe such a book? What about
updating it?

Makeready had some such material, but it was really a collection of columns on various production-related topics, food for thought more than a production guide. I may make a new edition of it at some point, but it is not currently my priority.

I am in the early stages of a new version of Professional Photoshop, but what's going to be in it definitely needs to be reconsidered in view of the unexpected results for the LAB book, which, to the stupification of both myself and the publisher, continues to be the #1-selling book in the entire computer-related field. So, in the next week or so, I'll probably be throwing some ideas out for feedback from the group.

I hope your copy of Canyon Conundrum makes it to Norway soon.

Dan Margulis
____________________________________________________________________________

   Date: Thu, 1 Sep 2005 19:46:58 EDT
   From: Dan Margulis
Subject: Re: You're Number One

I would ask that for future updates you make it clear about the year it
came out...I got the wrong version of Professional Photoshop from Amazon because
it wasn't clear which version was newest. Of course I can see why publishers
might not want to be clear on that...they sold me a book that I wasn't looking
to buy.

Those who were on the list in 2001 may recall that there was considerable discussion of the titling of this book, all of which got forwarded to and discussed with the publisher in advance of the final decision. Coincidentally, the publisher of Canyon Conundrum is not the same one as that particular version of Professional Photoshop. I think it likely that future versions of both books, if any, will make clear whether they are "second edition", "fifth edition" or what.

Dan Margulis
____________________________________________________________________________

Date: Fri, 02 Sep 2005 08:11:13 -0400
   From: Ted Lane
Subject: Re: Eighteen Questions about Dan's new LAB book

At 9/2/2005 05:53 AM, Dan Margulis wrote:

6. At this point the evidence is overwhelming that there is no 16-bit
advantage in dealing with color photographs. A few people argue otherwise,
but it has now become a matter of religious belief, rather than reliance on
demonstrations that they can't provide.

I see the above quote refers to "color" photographs. Does the same finding hold true for images converted to Black & White from a color capture?

Thanks for your help,

Ted
____________________________________________________________________________

   Date: Fri, 02 Sep 2005 13:13:47 -0000
   From: Stephen Marsh
Subject: Re: Eighteen Questions about Dan's new LAB book

---Ted Lane  wrote:
 
I see the above quote refers to "color" photographs. Does the same
finding hold true for images converted to Black & White from a color
capture?

Thanks for your help,

Ted, this has come up in the past. Probably in one of these two archives, if not it is here, I remember the thread/s.

http: //www.ledet.com/margulis/ACT_postings/ACT-8-bit-16-bit.html

http: //www.ledet.com/margulis/ACT_postings/ColorCorrection/ACT-16-bit-2002.htm

The upshot is, that yes, it can in theory help as there is only one channel, but if I remember correctly, Dan's position is that the quality gained from making all tonal corrections in the full colour original before conversion to monotone in 8bpc is the 'correct' workflow. While most users I encounter would just convert to single channel mode or mix R==G==B and then use levels/curves - thus they loose the advantage of correcting the full colour image having three/four channels with different data...so thus the use of high bits may be more evident in this common but 'incorrect' choice of workflow.

If productivity is not an issue, I scan in high bit for colour or greyscale originals...but time is usually of the essence, so most colour original scans are 8 bpc for one off use. If scanning a greyscale original, then I do use high bits, as the trade off is less than for a colour image at the same size and it will be taken down to regular bit depth after the major tonal edits anyway (one off use).

P.S. Here is a quote from Dan:

" Date: Tue, 21 May 2002 13:53:26 EDT
From: Dan Margulis
Subject: RE: 8x16 bits to Dan:What about BW?

    André writes,

    I've been following the thread about 8 x 16 bits editing,and a
question came to my mind? Are the considerations you made valid for BW
images, or can we severely degrade the image doing tonalmanipulations
in 8 bits/pixel?

    Technically there is more of a case for 16-bit in B/W than in
color images, however it's unlikely to make any real difference.

    Bit depth works along the same lines, although it doesn't have
nearly as pronounced an effect as, resolution. The higher the
resolution of the original capture, the more pixels have to be
averaged to achieve final output. This results in more smoothness,
more consistency--if that's what you really need. It results in
oversoftness, lack of focus, if it's not. Similarly, less resolution
provides a crisper, snappier look, if that's what you want, or a harsh
and jagged look if it isn't.

    One can vary resolution quite a bit without hurting anything but
it's definitely possible to scan at a resolution that is so high that
it actually harms quality, just as it is to scan at a resolution so
low that the result will be disagreeable.

    Varying bit depth has a similar effect, but much less of it. That
is, pictures corrected in 8-bit will, if the correction was very
aggressive, seem very slightly sharper than those done in 16-bit.
While the difference is basically inconsequential, if we held a gun to
people's head and forced them to choose between two color images, most
of the time, if they saw a difference at all, they would choose the
one corrected in 8-bit. Some of the time, of course, they'd choose the
16-bit version.

    In color, having extra channels softens the image, taking away
some of the 16-bit advantage. If one channel is extra harsh it's not
such a big deal. In B/W, this effect doesn't exist, so there would be
a lot more cases where one might have a slight preference for a 16-bit
correction.

    Dan Margulis"

Stephen Marsh.
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 10:15:38 EDT
   From: Dan Margulis
Subject: Re: You're Number One

Iliah posts the following quote from another person:

I have been finding new ways to PP [post-process] my shots for years
now....this by far absolutly BLOWS AWAY any PP techniques I
have learned to date.

The big argument about how the book would be received was whether people without a LAB background would be able to get immediate results from the first few chapters. I did not know whether this would be so, because in my classes the students get to watch me demonstrate LAB techniques for a couple of hours before they venture into it themselves. Readers of the book have to find their own way.

I have seen around half a dozen such quotes so far. It's not quite enough to draw any firm conclusions. When the book came out, I thought we had plenty of time to hear from readers in September and October before figuring out what they were saying, and if it impacted future writing plans so be it.

Now, however, it is clear that we were completely wrong about how well this LAB book was going to be received, I need to reconsider what those future plans are, and I have to do it quickly. When a book is hanging out at #1 in sales, the publisher starts getting fairly insistent on immediate plans for a new one.

So, if people have feedback on this LAB book that either confirms or rebuts the quote that Iliah posted, it would be real helpful if you would send it to me either here or off-line, because some serious decisions will be made in the very near future. Also, I will be posting some specific questions for discussion within the next ten days, probably right after Photoshop World, which is Tuesday-Friday of next week.

FWIW, for a different perspective, David Biedny has started a podcast about Photoshop news, the first segment of which, among other things, devotes a lot of time to this book. It's accessible at http: //attentionphotoshoppers.libsyn.com

Be sure to select the FIRST podcast.

Dan Margulis
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 13:11:18 EDT
   From: Dan Margulis
Subject: Re: Eighteen Questions about Dan's new LAB book

Andrew Rodney, quoting me, writes,

With respect to the author you mention, in a recent thread on the ColorSync
list I repeatedly asked him whether he had ever personally run a test (or seen
anyone else perform such a test) where the same exact corrections were applied
in both 8- and 16-bit modes to a real-world color photograph, and compared
the results. He repeatedly refused to answer.

He has an example on page 24 of Real World Camera RAW.

No, he doesn't. He has yet another lame effort to blow smoke over his inability to produce a real example of 16-bit superiority.

The words EXACT SAME are not just there to take up space. The only way we can know whether 16-bit corrections are really better is to carefully compare, side by side, at a respectably large size, a 16-bit correction with one that was done the EXACT SAME way, except in 8-bit.

Instead, the example was produced in the following way.

1. Start with two identical files in Camera Raw. So far, so good.

2. Move File #2 into Photoshop and convert into 8-bit. So far, so good.

3. Correct the appearance of File #1 in Camera Raw. The "comparison" is now totally invalid, in that something has been done to File #1 that cannot be done to File #2.

4. Hack at File #2 with the master Levels slider until it has a slight resemblance to File #1. The "comparison" is now even more invalid, in that something has been done to File #2 that wasn't done to File #1, but the author declares that these two files are now equivalent.

5. Convert File #1 into 16-bit RGB.

6. Apply a new curve to both #1 and #2.

7. Output the two files at postage-stamp size, and announce that #1 is obviously much better than #2, wherefore 16-bit correction is better than 8-bit, QED.

If the files had been output at a size large enough for anyone to tell, #1 would indeed have looked much better than #2. We know this because the author thoughtfully provided histograms of both images after step 4, at a size large enough that their numerical readouts are legible. He never set a proper highlight in #2, and he did in #1, so of course #2 is flat and muddy in comparison to #1. The histogram for #2 starts far over to the left in every channel compared to the corresponding channel in #1. Even though the images *appear* to be of similar darkness, the mean/median pixel values for #1 are 150.61/166 and #2 they are 139.54/148.

So, in these two images that the author claims are similar enough to test as if they are equals, #2 is typically 12 to 18 levels darker than #1. Since the difference is happening primarily in the light areas, one would guess that his highlight in #1 is around 250r250g250b and in #2 230r230g230b, or in CMYK terms, around eight points heavier in each channel in the highlight. So, obviously, there is a massive loss of detail in the quartertones coupled with a muddying of all colors.

This comparison of "corrections" of two supposedly equivalent images was apparently so embarrassing that the author replaced it with a new image in his CS2 edition, but used the same fouled-up methodology. That is, #1 is corrected first in Camera Raw and #2 is not, while #2 gets some hack in Photoshop that isn't applied to #1. The author again declares the two to be equivalent, applies the same further curve to both, and proclaims victory when #2 looks like drek.

This time, the two don't even look alike at the outset--#2 is obviously much darker. Instead of having an overly dark highlight as in the previous edition, this new picture has the same tonal range as #1, but it's shifted sharply toward darker three-quartertones. The numbers aren't fully legible in my copy because the page was printed slightly out of register and the blacks weren't separated with Max GCR. However, what I can read shows at least a 10-level difference.

In short, the example in the CS version of the book demonstrates that when two otherwise similar images vary significantly in highlight value the one with the lighter highlight will be cleaner and higher-contrast; and that when you apply the same curves to two pictures one of which is much darker than the other, the shadows may plug in the darker one. But they prove zero about bit depth.

Now, it would have been a sufficient answer to Andrew's original statement to point out that the two images on which the "test" was based were produced in different manners and that therefore the test was meaningless. I reply at this length to make a point in response to a comment by Henry Domke about the use of the histogram.

As I remarked to Henry, a histogram is worse than useless in image correction, although it can be useful in image acquisition. And the numerical readouts are essential, as here, in determining how close two apparently similar images really are to one another.

I'm sure that this author actually believed that the two start images in each set were actually equivalent. The histogram and its readouts, however, demonstrate that they weren't even close. The author ran the graphics of the histograms because he believed that the sawtoothing in his #2 versions as opposed to the smoothness in his #1s was significant to reproduction, which it isn't. But he couldn't see that the tonal ranges of the images in his CS book were very different, which is critical, or that the shapes of the histograms in his CS2 book were different. And, he didn't read the numbers, which scream out that in both cases, the #2 versions are much darker than the #1 versions he thought were equivalent.

In short, it is painfully evident that this author, who advocates the use of histograms in image corrections, in fact cannot read a histogram himself. I say this not to bash this particular author, who is my friend, because I think that most if not all of those who advocate using histograms in correction wouldn't be able to read these histograms properly either. That is why, although I do use histograms myself in post-mortem analysis, I have never printed one in a book or article, because I think that they've done a lot more harm to the general public than they have good.

Dan Margulis
____________________________________________________________________________

   Date: Fri, 02 Sep 2005 11:56:39 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/2/05 11:11 AM, "Dan Margulis"  wrote:

No, he doesn't. He has yet another lame effort to blow smoke over his
inability to produce a real example of 16-bit superiority.

You are of course entitled to that opinion and the same could be said for the illustrations throughout your new book.

The words EXACT SAME are not just there to take up space. The only way we can
know whether 16-bit corrections are really better is to carefully compare,
side by side, at a respectably large size, a 16-bit correction with one that
was done the EXACT SAME way, except in 8-bit.

It1s only invalid because you say so.

I would agree that there are difference as one correction is happening in ACR (in linear encoded data), the other is happening in Photoshop in gamma corrected data. But the results speak for themselves.

If the files had been output at a size large enough for anyone to tell, #1
would indeed have looked much better than #2.

The problem with this 3debate2 is the rules keep changing. Now we have to define a size. I1ve all along said that in many, many cases, you1ll NEVER see the differences in output (at any size) between the two but that the output plays a role. Take your new book. Can I tell which images were worked in in 8bit versus high bit? Nope. I don1t think the print quality is that hot and even if you had super bright smooth paper and Hexachrome output, it1s again possible I1d not see the difference to a halftone dot. To a contone output like my Pictrography or a Lightjet or even worse, a film recorder, very possible. Since I have no idea where any of my files might be output, I prefer not to take the chance. If we agree that all output will be printed to the size of your book, with that repro quality, I1d probably agree that using high bit isn1t going to buy anyone anything. We could agree to use JPEG and super high compression of all we cared about was newspaper repro. That doesn1t alter the facts that there are situations where we could see the effects of such compression. If the size is small enough and the output conditions a certain quality, there1s no reason to worry about these artifacts.

This comparison of "corrections" of two supposedly equivalent images was
apparently so embarrassing that the author replaced it with a new image in his
CS2 edition, but used the same fouled-up methodology. That is, #1 is corrected
first in Camera Raw and #2 is not, while #2 gets some hack in Photoshop that
isn't applied to #1. The author again declares the two to be equivalent,
applies the same further curve to both, and proclaims victory when #2 looks like drek.
This time, the two don't even look alike at the outset--#2 is obviously much
darker.

I can1t comment on the CS2 edition (if you1re referring to the book on Photoshop, not ACR), I don1t have it. I can comment and did on the ACR book which I do have sitting in front of me. The before and after images in ACR version 1 (parrots) and version 2 (owl) are different but I don1t see what you describe on my copy.

Now, it would have been a sufficient answer to Andrew's original statement to
point out that the two images on which the "test" was based were produced in
different manners and that therefore the test was meaningless.

Only meaningless because you say so. As for the differences in the histogram, the question becomes, do you edit the secondary image to produce the same numbers even though one was edited in a linear encoded gamma and the other not or do you visually try and match them and let the numbers lay where the do? I think the two match visually very closely, at least in both copies of the books I have. He states that after editing in Camera RAW, further editing was applied in Photoshop. The author states which is a fact:

3The two images appear similar visually but their histograms are very different. (he admits it) One contains a great deal more data than the other. (true) Despite the vast differences in the amount of data they contain, it1s hard to see any significant differences between the two images-you may be able to see that one with more data shows more details on the chest feathers but it1s pretty subtle.2 (Note I do see a tad more detail. You could argue the author cheated and applied sharpening if you wish). 3Figure 2-4 shows what happens when a fairly gentle curve edit is applied to the images. The difference is no longer subtle!2 (agreed again).

I'm sure that this author actually believed that the two start images in each
set were actually equivalent.

He doesn1t state that. He states the facts that both the histogram and the images (in print) are dissimilar and he explains why. The most important point is this, that the high bit file has more editing headroom.

Andrew Rodney
____________________________________________________________________________

   Date: Fri, 02 Sep 2005 18:45:47 -0000
   From: "Ivan Histand"
Subject: Re: Eighteen Questions about Dan's new LAB book

--- In colortheory@yahoogroups.com, DMargulis@a... wrote:

 No, he doesn't. He has yet another lame effort to blow smoke over
his  inability to produce a real example of 16-bit superiority.
 
 The words EXACT SAME are not just there to take up space.

Dan, I appreciate your insight here.  Clearly the comparison referenced is really a comparison of workflows, not 16 vs 8 bit.  

That said, it does seem to me that there is some benefit to gain from doing some adjustments on the linear RAW data, no matter whether that data is 8/10/12/16 bits or beyond.  It's only a coincidence to this discussion that most current pro cameras capture 12 bit color.

What I'm hearing you say is that one should not adjust their workflow simply because "16 bit is better"  One should find a workflow that they are productive in, and not worry so much about how many bits are being pushed around.  If there are gaps in the histogram, so be it.  

I think a reasonable workflow when using Camera Raw is:

1. in CR, do first cuts to correct obvious cropping, color cast, and exposure issues.  Don't get too carried away with making it perfect, maybe spend 20 seconds on it.  Ignore the histogram, but turn on the clipping display to make sure you're not losing any important pixels.
 
2. output to photoshop in 8 bit and your preferred working space.  The conversion is done on linear data, so if there is any loss it should be minimal.  

3. make furthur adjustments in photoshop, both global and local, all in 8 bit.  Add adjustment layers, etc to your heart's content.  Use the "by the numbers" techniques that Dan advocates.

4. Output to your final destination(s), be it print or web.

As I see it, the real advantages of working in camera raw are workflow related.  For example it's really simple to copy a group of adjustments from one image and apply them to a whole mess of other images that need the same adjustment, without ever even opening up the other images.  In photoshop this can be done, but the process is much more difficult and time consuming, you'd probably need to record an action.  Again, this has nothing to do with 8 vs 16 bits, just the CR/Bridge vs PS interface.

Thanks again,
Ivan Histand
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 20:29:13 EDT
   From: Dan Margulis
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book

Henry Domke writes,

But is it possible to manipulate and increase color variability of
Red-Cyan like we can
Green-Magenta or Blue-Yellow by steep curves in the A & B channels?

Yes, you just work on A *and* B rather than A *or* B.

A question with a look to the future: I have heard some speculation
that at some point printers might support 16-bit files directly. Would that be a case
where there might be some advantage?

It would be helpful in processing computer-generated gradients that were not created in the output colorspace, particularly dark blue gradients that were created in RGB but need to be output in CMYK.

However, I don't think there is one illustration in this 366-page
book showing a layer mask.

Perhaps if you review my first message, which gives the figure number of just such an illustration, you will think differently. There are at least two other illustrations of the actual layer mask in the book, but inasmuch as you don't appear to be interested in hearing what the figure numbers are, I'll leave you to hunt them up yourself. In any event, your initial comment was "Why on earth doesn't Dan use layer masks for some of his corrections?" As we have seen, there are layer masks at various places throughout the book.

Instead, he repeatedly shows "Blend If" sliders.  To my
inexperienced way of thinking, Blend-If is a crippled version of a layer mask.

Blend If is just as editable and just as eligible for mode change as a layer containing a layer mask is. If you need to actually paint into the mask or otherwise alter it, then you need a layer mask. If Blend If is sufficient it makes no sense to take twenty times as long to construct a layer mask that probably isn't as accurate.

Also, I stress again that this is a book on LAB, and not Photoshop Classroom in a Book. Layer masks don't operate any differently in LAB than they do in RGB or CMYK. Blend If, OTOH, offers many opportunities in LAB that aren't available elsewhere, and which might not occur to the average user. It is entirely appropriate that a book on LAB would emphasize commands in which LAB makes a difference.

I never referred to the history palette or intermediate backup files.
However, if one creates their LAB curves on an adjustment layer, it leaves room to revisit the file for adjustments much more easily. As my father always said "Keep your options
open."

I think that, as children often do, you left the room before your father stopped talking. You missed the end of his sentence, which was "Keep your options open, if you think you might need them."

You appear to work with fine art reproductions. It certainly seems that you would want to be able to adjust curves after the client has seen one proof, so adjustment layers are eminently appropriate in your case. But you should not be imposing your workflow on others.

If, for example, you worked for a newspaper, in would come an RGB JPEG, and you would have three minutes to produce a workable TIFF from it. The correction that you do may be good or it may be bad but it will be final either way--there is virtually no chance that the file will ever be worked on again once it has printed. In these circumstances it would be quite mad to waste two-thirds of the allotted work time in saving a useless layered .psd document. There are more Photoshop users, IMHO, who have workflows where the first output is the final output than the other way around.

Do you not have an opinion on two (or three) step sharpening?

I show examples of two-step sharpening in Chapters 6, 7, and 16. Faster computers have enabled a lot of sharpening techniques that weren't available ten years ago and some fairly sophisticated variants have arisen. I know of at least nine credible strategies for applying a single sharpen, so there are an infinite number of two- and three-step sharpens possible.

Certainly one shouldn't apply the same type of sharpening twice to a picture, and in some cases if you are using two different sharpens you have to do them in a particular order. I've seen a few cases where more than two steps were mildly helpful but consider them to be curiosities.

What do you think of the concept of capture sharpening in addition to
output sharpening?

In principle I'm opposed, but in practice certain capture devices produce very soft images if there isn't a minimal amount of sharpening, so you're kind of stuck with it.

Lastly, thanks for writing another thought provoking book. Your
thinking and writing style are outstanding. It is fun to disagree with you.

My pleasure.

Dan Margulis
____________________________________________________________________________

   Date: Fri, 02 Sep 2005 21:32:23 -0400
   From: "Gene Palmiter"
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book

Well...about a year ago I started putting a lot of study into adjustment layers and layer masks. I figured that was when I moved from beginner to intermediate with Photoshop. I have some proficiency with that now and am looking for the next step. Blend if might just be the bow in the quiver I need to move further and I am glad to know that my soon to be arriving book on LAB will covering some of the benefits of this feature.

There is another area where I am weak and that is blend modes. I have to move down the list and try a bunch of them to see if any will help. I don't know if an expert on color adjustment would be the one to write a book on blending modes....but it doesn't hurt to bring it up.

Thanks,
Gene Palmiter
(visit my photo gallery at http: //palmiter.dotphoto.com)
freebridge design group
www.route611.com & Route 611 Magazine
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 20:50:08 -0600
   From: Ron Kelly
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book

Gene:

I too am weak on blend modes.

What I would like to see is a good explanation of what they do and why it might be useful, along with examples of course. I've read blending mode explanations before but none seemed to cut through the fog well enough.

I can't seem to get my head around this so that when someone demonstrates a good implentation of a blend mode I smack my head and say "Why didn't I think of that?"

Ron Kelly
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 20:33:00 -0700
   From: Rick Gordon
Subject: Blending Mode Book (WAS: Response to Margulis's answers my 18 Questions about LAB book)

And when this tome is written, it would be ideal to explore the potentials within RGB, Lab, and CMYK working spaces, as they differ.

For instance, intense blending modes such as Vivid Light and Linear Light, which can be overwhelming except at very low percentages in RGB, can be used very effectively in this Lab-oriented situation:

1) Starting with and RGB file, duplicate it and change the duplicates color mode to Lab.

2) In the original file, make a duplicate layer in Normal blending mode.

3) Use the Apply Image command to apply the A channel of the duplicate to the RGB composite channel of the original using Vivid Light or Linear Light as the blending mode (just as Dan has often suggested using Soft Light or Overlay for the same purpose).

4) The result will be that greens (such as foliage) will darken and reds will lighten, more so than with the aforementioned modes, but within a still very usable range, even at or near 100% blending. The range of blue/yellow variance within the greens will also increase.

5) Then this can be modified by setting the duplicate layer's blending mode to Darken (instead of Normal), thus affecting only the greens and not the reds, or to Lighten, which would affect the reds but not the greens.

6) If you wanted to affect the luminosity and color intensity to different levels, [Command-Option-Shift-E], eliminate or hide the original layer, and then set one copy of the of the stamped layer to Luminosity and another to Color, set at differing percentages.

The other possibilities are countless. Discount nothing as useless (or even only for hack effects). A few percent of something overwhelming can be very effective when its just used subtly.

Too many years ago, David Biedny wrote a groundbreaking book called "Photoshop Channel Chops." In it, he discussed blending modes and the Calculate function in depth. Now Photoshop offers many more blending modes and much more flexibility. There is a major book yet to be written on the subject. (Gee, why don't I try to write it?)

Rick Gordon
 
___________________________________________________

RICK GORDON
EMERALD VALLEY GRAPHICS AND CONSULTING
___________________________________________________

EWWW:   http://www.shelterpub.com
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 23:32:03 EDT
   From: Dan Margulis
Subject: Re: Re: Eighteen Questions about Dan's new LAB book

Ivan writes,

it does seem to me that there is some benefit to gain from
doing some adjustments on the linear RAW data, no matter whether that
data is 8/10/12/16 bits or beyond.  It's only a coincidence to this
discussion that most current pro cameras capture 12 bit color.

Just as it's a coincidence that Camera Raw works with linear data. The relevant things are that Camera Raw handles big changes well and that it allows us to easily apply the same correction to a series of images.

What I'm hearing you say is that one should not adjust their workflow
simply because "16 bit is better"  One should find a workflow that
they are productive in, and not worry so much about how many bits are
being pushed around.  If there are gaps in the histogram, so be it.

Right.

I think a reasonable workflow when using Camera Raw is:
1. in CR, do first cuts to correct obvious cropping, color cast, and
exposure issues.  Don't get too carried away with making it perfect,
maybe spend 20 seconds on it.  Ignore the histogram, but turn on the
clipping display to make sure you're not losing any important pixels.

Well, actually, if you only have 20 seconds, probably you should make sure that you aren't losing *any* pixels, because you really don't have time to check out whether they are important or not. But that's a quibble. The real message, with which I entirely agree, is that when the image has obvious problems, you should try to correct them somewhat in Camera Raw. But you should be conservative. No reckless gambles that would ruin the image and force you to start again from scratch if you blow out detail.

As I see it, the real advantages of working in camera raw are workflow
related.  For example it's really simple to copy a group of
adjustments from one image and apply them to a whole mess of other
images that need the same adjustment, without ever even opening up the
other images.  In photoshop this can be done, but the process is much
more difficult and time consuming, you'd probably need to record an
action.  Again, this has nothing to do with 8 vs 16 bits, just the
CR/Bridge vs PS interface.

Right on all counts.

Opening a file in Camera Raw is a lot like drum scanning, and to some extent it's like working in LAB also. Very powerful tools, but clumsy. The mistake a lot of people make is to try for perfection with them. One can, given enough time, produce highly creditable final files with any of the three--in a lot longer time than it would take to do the same work in Photoshop proper.

Most people have little difficulty making a really good image out of a pretty good one. The problem arises when you area supposed to make a really good image out of a pretty *bad* one. RGB and CMYK don't do this very well. A drum scanner, Camera Raw, or LAB have the power to make a pretty bad image into a pretty good one--one that can easily be finalized in RGB or CMYK.

That last sentence is just for emphasis. I agree with the entirety of what you posted.

Dan Margulis
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 23:33:22 EDT
   From: Dan Margulis
Subject: Re: Eighteen Questions about Dan's new LAB book

Andrew Rodney writes,

I would agree that there are difference as one correction is happening in
ACR (in linear encoded data), the other is happening in Photoshop in gamma
corrected data.

Good! Now that we agree that these are not the same exact corrections, we can agree that your earlier statement, which is what provoked my response, has become inoperative (direct, unedited quote):

DM: "I repeatedly asked him whether he had ever personally run a test (or
seen anyone else perform such a test) where the same exact corrections were
applied in both 8- and 16-bit modes to a real-world color photograph, and
compared the results. He repeatedly refused to answer."

AR: "He has an example on page 24 of Real World Camera RAW."

Dan Margulis
____________________________________________________________________________

   Date: Fri, 2 Sep 2005 22:49:25 -0600
   From: Ron Kelly
Subject: Re: Blending Mode Book (WAS: Response to Margulis's answers my 18 Questions about LAB book)

On 2-Sep-05, at 9:33 PM, Rick Gordon wrote:

 And when this tome is written, it would be ideal to explore the  
 potentials within RGB, Lab, and CMYK working spaces, as they differ.

 For instance, intense blending modes such as Vivid Light and Linear  
 Light, which can be overwhelming except at very low percentages in  
 RGB, can be used very effectively in this Lab-oriented situation:

 The other possibilities are countless. Discount nothing as useless  
 (or even only for hack effects). A few percent of something  
 overwhelming can be very effective when its just used subtly.

(The sound of a smacking head!)

And now for the dumb question: how did you come to this idea in the first place? It just seems totally bizarre to have tried this. I will accept that it may be very effective; I plead lack of time to try it at present.

Right now I'm going to tuck in with a new book on Lab but someday not too far off I shall point my compass into blending modes research.

As ever, hats off to the brave souls who fight back fhe frontier, making the universe safer for us timid souls. Andromeda Galaxy will have to wait.

Ron Kelly
____________________________________________________________________________

   Date: Sat, 03 Sep 2005 10:10:33 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

To add another interesting twist. Take the high bit file and duplicate it. Zoom into one at 1600% (yes, we want to see at the pixel level). Find an areas with pretty dark pixels (8-12 value). In CS2 you can match zoom and location and with both files are side by side, you can now see 3before and after2. Now convert one to 8-bit. Anyone seeing a difference at this point, before even applying corrections? It1s subtle but I see it on my Artisan. It almost looks like a tad of USM was introduced. That is, the smoothness of similar pixels appears to be more pronounced just by converting to 8-bit. Only appears in darker tones.

Andrew Rodney
____________________________________________________________________________

   Date: Sat, 03 Sep 2005 09:56:47 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/2/05 9:33 PM, "Dan Margulis"  wrote:

 DM: "I repeatedly asked him whether he had ever personally run a test (or
 seen anyone else perform such a test) where the same exact corrections were
 applied in both 8- and 16-bit modes to a real-world color photograph, and
 compared

I have such a file which I posted on my site for anyone to download. Unless I1ve suffered a major brain fart (or once again, the rules change), its quite clear to me that the 16-bit file is showing vastly superior quality with respect to noise and artifacts compared to the 8-bit file.

The image  was shot with a Canon 350D (ISO 100). I used Adobe Camera RAW 3.X with all defaults and auto settings OFF. No sharpening in ACR either. The file was brought into Photoshop in 16-bit in ProPhoto RGB from ACR. Then I duplicated the file and converted the dupe to 8-bit. I applied levels corrections (nothing super radical), USM and a boost in saturation (+20 in Hue/Sat). The IDENTICAL corrections were made on the high bit file (hold down option key and the other key command to call levels, USM etc to get exact values) or drag and drop history from one to the other.

Cache is off In histogram. The 8-bit Histo isn1t awful like I see in Bruce1s book. But there is a very noticeable amount of noise in the 8-bit file not seen in the high bit file. I also converted from ProPhoto into LAB and did the same corrections (well not exactly since levels in LAB can1t be duplicated exactly as you would from an RGB file). Again, the 8-bit file shows severe noise introduced by the corrections that simply don1t show up in the high bit file. At 200% zoom, it shows up like a sore thumb.

I1ve taken a section of the image since in high bit, it1s quite large and cropped it down as the 16-bit ProPhoto RGB file. In the zip archive are screen dumps of the corrections made. I also generated a Photoshop action; one duplicates the 16-bit file, converts to 8-bit and applies the three corrections. The 2nd would be used on the original (doesn1t duplicate) making a bit easier to apply both sets of corrections.  After that, zoom into the green (slightly out of focus) bird feeder at 200% and look at the differences. The biggest issues in the 8-bt file appear to show up in shadows which makes sense. This is another reason why even superior quality would be produced on linear encoded data within ACR. It also illustrates the need to 3expose to the right2 for RAW data since the first 2048 steps of data are all within the first stop of highlights.

This is a real world image and the corrections are not severe and identical on each. The Zip archive is about 1.8mb.

I1m seeing this effect on other files shot and processed in this manner. I can of course supply the RAW data but it1s pretty large. If anyone wants it, let me know and I'll put it on my public idisk.

The file is here:

http://www.digitaldog.net/files/16bitchallange.zip

Andrew Rodney
____________________________________________________________________________

   Date: Sat, 3 Sep 2005 16:28:41 -0700
   From: Lee Varis
Subject: Re: Eighteen Questions about Dan's new LAB book

Thanks Andrew, I've been looking for a file that demonstrated why it is a bad idea to work in ProPhoto RGB - now you've provided a perfect demonstration.

Unfortunately its not really that clear to me that this demonstrates "vastly" superior quality for a 16 bit workflow unless you need to lighten and saturate severely underexposed images in ProPhoto RGB.

What we have here is a file in ProPhoto RGB that contains no colors that would fall outside of Adobe RGB. Most of the bits available in ProPhoto RGB are not being used in this image. When I convert the 16bit ProPhoto RGB file into 16bit Adobe RGB and run your test I see no difference between the 16bit and the 8bit version!

I've posted a screenshot here:

http://www.varis.com/ColorTheory/16bitchallenge.jpg

What is interesting is that you can see a difference when this operation is conducted in ProPhoto - the fact that the difference is not noticeable in print at a reasonable output size works against your claim that it shows a "vastly" superior quality with respect to noise and artifacts. When shown prints (Epson R2400, image at 240 ppi print @ 2880) of the two versions my 17 year old son (who happens to have better eyesight than me) picked the 8 bit version as better because it seemed a tiny bit sharper!

I will admit though that if you insist on using a workspace that is vastly larger in color gamut than you really need for any type of printed output you'll have smoother results if you do your adjustments in 16bit.

Here is a screenshot demonstrating the difference side by side:

http: //www.varis.com/ColorTheory/16bitchallengeProPhoto.jpg

It is interesting to note how much worse the 8bit ProPhoto file looks than the 8bit AdobeRGB file. I think that its quite possible that if you output a continuos tone print (like a Lightjet) and put a loupe on the print you could see the noise and artifacts on the ProPhoto version.

Here is a screenshot showing ProPhoto vs AdobeRGB versions:

http: //www.varis.com/ColorTheory/8bitProPhotoVS8bitAdobeRGB.jpg

The bottom line -- if you must use ProPhoto RGB stay in 16bits for major adjustments. Otherwise, use Adobe RGB and you can do everything in 8bits.

regards,

Lee Varis
http://www.varis.com
888-964-0024
____________________________________________________________________________

   Date: Sat, 3 Sep 2005 19:46:52 EDT
   From: Dan Margulis
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book

Ron Kelly (and Gene Palmiter and Rick Gordon similarly) writes,

What I would like to see is a good explanation of what they do and  
why it might be useful, along with examples of course. I've read  
blending mode explanations before but none seemed to cut through the  
fog well enough.

Well, here we go, I was going to start the discussion in a few days but it appears to have started itself.

The question is: sometime in 2006, there will be a fifth edition of Professional Photoshop. Those familiar with the series know that, unlike any other Photoshop series I know of, each edition is drastically different from the previous one--at least 50% new content, and in one case as much as 80%. The last edition appeared in early 2002; there will therefore be a four-year hiatus between editions.

The LAB book took a lot of time. If it turned out that it was a bust in the market, my plan was to make relatively slight revisions in Professional Photoshop, meaning 20% or so, and just leave it at that. Given the actual results, I am not inclined to do a halfway job on the next edition, plus I have to cope with a publisher who suddenly has gotten much more interested in a relatively early appearance thereof. Consequently I have to make certain decisions fairly quickly and would be interested in suggestions from the group.

The only part of the book that dates from 1994 (although it's been strongly revised since) is the section on the role of black. The parts that date from 1998 are sharpening, and introductory blending. Everything else originated either in the 2000 or 2002 editions. The major Photoshop developments since the 2002 edition have been the Shadow/Highlight command, and Camera Raw.

The early feedback from the LAB book is that there are a lot of users, particularly serious photographers, who are astounded at the effectiveness of the simple curves shown in the first four chapters, to the point that some of their posts sound delirious. (I have no reader feedback at all on anything past p.100). Now, this is good news and bad news. Of course it makes me feel good about the LAB book, but it isn't a very good compliment for the presentation of LAB in Professional Photoshop. The information was all there, but apparently it was just presented too quickly for a lot of people to grasp.

The next edition, therefore, will have a kinder, gentler presentation of LAB, omitting the fancy overlay blending stuff. I suspect I should do the same thing with the blending information being referred to above. Definitely I intend to trash the current presentation and start from scratch. I don't think, however, that I should go much beyond the most common types of blends to correct luminosity and color. I believe we have to make sure that the readers can get the basics right.

With respect to sharpening, I think the 1998 explanation of conventional sharpening still is valid. Many other approaches are now known, however. Plus, I think the best explanation of the Shadow/Highlight command is as a specialized type of sharpening. So, while the current chapter will stand largely as is, I plan to add a couple of chapters on these topics.

I agree with the posters that an entire book could be written on blending. A book could also be written on sharpening. I don't think that either one is economically viable. If, when this next edition is finally out, the LAB book has racked up monstrous sales, then maybe that would indicate that there was a market for a really advanced blending book and I'd have to rethink this position.

As for curving and color by the numbers, the current structure works for me. I intend to make clear earlier, however, the close relationship between CMY and RGB, because I am sick of hearing people saying they are very comfortable in one but can't possibly be expected to work in the other. In the current market, professionals need to be able to handle both.

And speaking of the current market, it's obvious that the types of images that professionals/serious amateurs have to deal with are different from they were four years ago. I would like to kill almost all of the stock photography in the current edition (except some particularly instructive examples) and replace it with real-world work and real world problems. To that end, I will ask list members to help support the project with images, as I did with the LAB book. But, I don't know yet what types of images to ask for--that's the purpose of this message.

So: for discussion. What *categories of image* would you particularly like to see treated in the next edition of Professional Photoshop? Also, I'm comfortable with the format described above, but it isn't set in stone. So, comments or criticism of it are welcome.

I'm off to Photoshop World on Monday, so I won't be participating much in the list during the week. For those attending, in addition to my scheduled seminars, I will be discussing LAB in the Peachpit Press booth on the show floor at noon on Thursday.

Thanks, as always, for any suggestions.

Dan Margulis
____________________________________________________________________________

   Date: Sat, 03 Sep 2005 19:12:24 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/3/05 5:28 PM, "Lee Varis" wrote:

 Thanks Andrew, I've been looking for a file that demonstrated why it
 is a bad idea to work in ProPhoto RGB - now you've provided a perfect
 demonstration

Bad? Works fine in high bit. If you happen to shoot in RAW, you'll find lots of images that fall way outside say Adobe RGB (1998) but within ProPhoto. So if you are OK clipping color from your capture device go that route. Otherwise, ProPhoto RGB is a better space to contain those colors.

 Unfortunately its not really that clear to me that this demonstrates
 "vastly" superior quality for a 16 bit workflow unless you need to
 lighten and saturate severely underexposed images in ProPhoto RGB.

Lighten, sure. Saturate why not? And if you try corrections other than saturation (like just lighten), you'll see the benefits of the high bit file in reduced noise.

The original argument was, using 8-bit versus high bit on a file (color space not defined nor should it be necessary), show an example where there's a benefit to to doing the same exact corrections on each. Do you see that or not?

What we have here is a file in ProPhoto RGB that contains no colors
that would fall outside of Adobe RGB.

The color in the file is immaterial. I'll be happy to shoot a saturated image that also contains dark shadows (gee, that's not hard to find) and illustrate noise in the shadows from the 8-bit corrections that are not produced in high bit.

Most of the bits available in
ProPhoto RGB are not being used in this image. When I convert the
16bit ProPhoto RGB file into 16bit Adobe RGB and run your test I see
no difference between the 16bit and the 8bit version!

Agreed, as I tried this in Adobe RGB (1998) as well and like you, saw far less issues. But that's not what the challenge is about, it's to show the benefit of using high bit versus 8-bit identical corrections. Plus why limit the color gamut? Did you try this on a LAB file? It shows the same issues. LAB's going to be also very large and produce the same issues in a different way. The high bit corrections do not exhibit the noise.

What is interesting is that you can see a difference when this
operation is conducted in ProPhoto - the fact that the difference is
not noticeable in print at a reasonable output size works against
your claim that it shows a "vastly" superior quality with respect to
noise and artifacts.

You printed it on what device at what size? You've got a tiny section of a full rez file.

When shown prints (Epson R2400, image at 240 ppi
print @ 2880) of the two versions my 17 year old son (who happens to
have better eyesight than me) picked the 8 bit version as better
because it seemed a tiny bit sharper!

Sure it does, look at the noise which produces on edges the look of more contrast. But that's non image data that's being formed due to the edits in 8-bit and it's not a good thing! We're seeing the effects of the edits causing aliasing in the form of noise.

I will admit though that if you insist on using a workspace that is
vastly larger in color gamut than you really need for any type of
printed output you'll have smoother results if you do your
adjustments in 16bit.

Yes, I and many need this large a working space to contain colors their capture devices produce. Looking at the gamut of my Imacon scanner, it too produces colors outside of Adobe RGB (1998) in many areas. I'd like to keep those colors since I can illustrate output devices that have gamuts that can use some, certainly not all, but some of that gamut. I also want a working space that has a large enough size to define dark colors that can't be kept in something like Adobe RGB (1998). That's a major benefit of such a space. Unlike output devices, the gamut shape of a working space is such that it tapers rather radically as it moves to darker tones. Output devices generally have a much wider gamut shape. When you use a smaller gamut working space, you crunch a good deal of data in those areas and end up printing blobs instead of detail in images that would have say very dark brown tones.

It is interesting to note how much worse the 8bit ProPhoto file looks
than the 8bit AdobeRGB file. I think that its quite possible that if
you output a continuos tone print (like a Lightjet) and put a loupe
on the print you could see the noise and artifacts on the ProPhoto
version.

I've got a Fuji Pictrography 4500 and I agree with you, it can be seen.

But that isn't the issue. The issue is I don't have to worry as much about this in high bit by applying the identical edits to this and many other images from this capture device. And I can do even more work with less damage using Adobe Camera RAW in linear encoded editing on high bit. That wasn't even accounted for here since the original post by Dan discussed how in Bruce's book, the two edits on page 24 were apples and oranges. We should see even better quality data first doing the tone mapping I did on the gamma corrected data in high bit instead in ACR.

The bottom line -- if you must use ProPhoto RGB stay in 16bits for
major adjustments.

So you agree that there's some advantage of high bit editing, all corrections being equal? I suspect the forum host doesn't agree with that or at least, has been asking for side by side comparisons. I don't recall the working space being part of this challenge.

Andrew Rodney
http://www.digitaldog.net/
____________________________________________________________________________

   Date: Sat, 3 Sep 2005 21:02:39 EDT
   From: Dan Margulis
Subject: Re: Eighteen Questions about Dan's new LAB book

Andrew Rodney writes,

The image  was shot with a Canon 350D (ISO 100). I used Adobe Camera RAW 3.X
with all defaults and auto settings OFF. No sharpening in ACR either. The
file was brought into Photoshop in 16-bit in ProPhoto RGB from ACR.

First of all, thank you for posting it, I agree that it is a real-world picture with real-world corrections. I have played with it a little bit but won't have any final comments until I get a chance to manipulate it more, which will be after Photoshop World. At that time, I will probably take you up on the offer to provide the raw file, provided you are willing to give me permission to publish it.

It would not surprise me if this or a similar file containing mostly dull colors, if left in ProPhoto RGB, would get a better result from 16-bit correction than 8-bit. I have tested Adobe RGB, ColorMatch RGB, LAB, and sRGB files enough to be highly doubtful that there are any natural color photographs at all where the extra bits would be helpful in any real-world context. However, I've always pointed out that I have *not* extensively tested exotic alternatives, such as 1.0 gamma files, or ultra-wide gamut RGBs such as ProPhoto. The reasons they are not tested are 1) they have limited market presence and 2) I strongly recommend against their use in color correction.

I do have another ProPhoto file where 16-bit definitely produced a better result than 8-bit. However, it was not a real-world exercise in that the file was intentionally sabotaged in Camera Raw by moving the exposure slider all the way to the left when the actual final intent was to lighten the file. We did repeat the same exercise, including the sabotage, with the same file output to Adobe RGB, and there was no problem with the 8-bit correction.

During the tests for the LAB book I was working with Wide Gamut RGB rather than ProPhoto, and it did astonishingly badly in all manner of conversions, from which I surmise that ProPhoto might as well.

In any case, if it turns out that in some cases 16-bit correction works better in ProPhoto RGB, I have no problem admitting it and adding that to the long list of reasons why one should avoid adjusting images in such a space.

Dan Margulis
____________________________________________________________________________

   Date: Sat, 03 Sep 2005 23:17:02 -0400
   From: Iliah Borg
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book

Most of the responses I'm reading are concentrated around symmetrical moves in "a" and "b" and sharpening L channel. Blurring "a" and "b" ad well as "Man from Mars" moves are getting their portion of wows, but it is substantially less understood for now. Past page 100 - blown-out highlight touch-up, from page 230, as well as moire treat (p. 239) are considered most important (and yes, I remember the "He still finds it difficult to believe this is a problem we see with any kind of regularity"). As usual, masks from channels and blending is less understood. That is slow-burning kind of knowledge, so to say. Takes time to get it under the skin :) The book is discussed on forums, and slowly we will understand more from it. For now many images produced using colour enhancement moves look overcooked to my eyes.

One common negative point is the quality of illustrations' prints.

The timing for the book is perfect IMHO, as with the start of the fall people look for strong colour contrast.

Poor exposure technique, limited dynamic range of digicams (especially if the exposure is wrong), noise, white balance problems, faded colours of high ISO shots, chroma noise in shadows, poor sharpness of consumer-grade superzooms, moire on architecture and portrait shots and many other aspects call for advanced post-processing. As far as I can see, amateur photographers are finding treats for some of these in "The Most Powerful Color Space".

Best regards,
ib
____________________________________________________________________________

   Date: Sat, 03 Sep 2005 21:40:54 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/3/05 7:02 PM, "Dan Margulis"  wrote:

I will probably take you up on the
offer to provide the raw file, provided you are willing to give me permission
to publish it.

Actually I1d like to find an image that is photographically more interesting! You1re only seeing a tiny section but trust me, it1s not at all much to look at in total. I should have no difficulty finding or shooting images with this camera in RAW that shows similar, perhaps even better demonstrations of the two options in processing. I1d also like to see the effects with different ISO settings. With 100 ISO, I1m producing the best possible image quality from this sensor. Lastly, exposure could play a big role here (using the expose to the right dogma).

It would not surprise me if this or a similar file containing mostly dull
colors, if left in ProPhoto RGB, would get a better result from 16-bit
correction than 8-bit. I have tested Adobe RGB, ColorMatch RGB, LAB, and sRGB files
enough to be highly doubtful that there are any natural color photographs at
all where the extra bits would be helpful in any real-world context.

ProPhoto is certainly a space that contains colors that are way out there. In fact, I1d agree in this context that some of the colors it can define are actually imaginary colors, a term you use in your new book that outside of ProPhoto RGB is a lose term I don1t agree with. In LAB (well CIEXYZ of which LAB is based) as well as the spaces you mention above, the colors are not imaginary but they can certainly be outside of the gamut of a lot of devices. In ProPhoto, there are blues that are outside human gamut which I think are absolutely imaginary (and of course unprintable). There are so called 3imaginary2 colors in Adobe RGB (1998) if the device trying to 3imagine2 them is a four color press.

The reason ProPhoto RGB is so large and why it1s necessary is we are often trying to fit square pegs in round holes if you forgive the analogy. The gamut of a digital camera (which arguably has no real color gamut) can be quite large. There are many, many real world scenes and thus images that fall far outside the gamut of Adobe RGB (1998) but can be contained in ProPhoto RGB. While there are those that say a histogram is an over used diagnostic tool, and I would not totally disagree, the histogram in Adobe Camera RAW provides a very non ambiguous way to see if the scene data falls outside Adobe RGB (1998) but within ProPhoto RGB. One could argue we need a working space with a gamut between the two. However, when I capture a scene, I want to have at my disposal all the color that device can provide. Today, the only way I can do this with a great deal of images is to use ProPhoto RGB. Even though it1s gamut is so large that it falls in some portion outside of human gamut, the other larger areas are necessary to contain other useful and I would submit non-imaginary and reproducible colors (to some devices).  

If you have a decent DSLR and Adobe Camera RAW, it isn1t too hard to open an image and find clipping of some or all primary colors in Adobe RGB (1998) by viewing the ACR histogram. Toggle to ProPhoto RGB and those colors can be contained when rendered and encoded into that working space.

Many of us have advised the use of high bit color with very wide gamut editing spaces and based on this one test, I think that1s a good call. It also shows the advantages of high bit data!

However, I've always pointed out that I have *not* extensively tested exotic alternatives,
such as 1.0 gamma files, or ultra-wide gamut RGBs such as ProPhoto.

I don1t think ProPhoto RGB (previously known as ROMM  RGB and around almost as long as Adobe RGB (1998)) is exotic. Anyone working with RAW files from digital cameras can find it a useful color container. It1s one of the four options in Adobe Camera RAW. As more images are captured digitally in RAW, if anything, the use of such a space will grow.

The reasons they are not tested are 1) they have limited market presence and 2) I strongly
recommend against their use in color correction.

ROMM RGB has been thoroughly tested and has been used for years. With the exception of using it with 8-bit files, the real downside I see is it could contain colors that fall well outside display gamut. But that1s true for 98% of every display on the market when you substitute Adobe RGB (1998) for ProPhoto RGB. I1d also rather have colors I might be able to use on output and perhaps not fully see on a display then throw away colors I know my various output devices can use just to see every color. And we both know that even with wide gamut displays, there are CMYK colors they can1t reproduce even if we started with a much smaller color space. In this context, those colors are imaginary but reproducible on press.

I do have another ProPhoto file where 16-bit definitely produced a better
result than 8-bit. However, it was not a real-world exercise in that the file
was intentionally sabotaged in Camera Raw by moving the exposure slider all the
way to the left when the actual final intent was to lighten the file.

In this file, I simply used the default settings but without the auto check boxes. The file does look dark on the Artisan but I didn1t have to do anything radical with levels to make the image look better. I would certainly have done this in ACR but then if I made the RAW to rendering file look as good as I could by simply clicking on the auto check boxes or using a custom setting, the data, even in 8-bit would look great and there would be little need to edit the file.

We did repeat the same exercise, including the sabotage, with the same file output to
Adobe RGB, and there was no problem with the 8-bit correction.

As Lee pointed out, in Adobe RGB from the RAW data, the same corrections do not produce the level of obvious noise in 8-bit. But I want and do use ProPhoto RGB for reasons discussed as do many other users.

In any case, if it turns out that in some cases 16-bit correction works
better in ProPhoto RGB, I have no problem admitting it and adding that to the
long list of reasons why one should avoid adjusting images in such a space.

Well that1s certainly a good step forward. NOW we need to test what ProPhoto brings to the party but we have to do so with current output technology (meaning more than four color ink on paper) and with an eye on future print technology.

Andrew Rodney
http://www.digitaldog.net/
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 00:07:51 -0400
   From: Iliah Borg
Subject: Re: Eighteen Questions about Dan's new LAB book

As one of those involved in programming raw decoders, I will certainly agree with Andrew's point about Adobe RGB being too limiting for mapping colours found in images from most recent cameras worth a buy.

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 00:12:16 EDT
   From: Dan Margulis
Subject: Re: Blending Mode Book (WAS: Response to Margulis's answers my 18 Questions about LAB book)

Rick Gordon writes,

For instance, intense blending modes such as Vivid Light and Linear Light,
which can be overwhelming except at very low percentages in RGB, can be used
very effectively in this Lab-oriented situation:

Congratulations on coming up with a novel and effective approach. In the LAB book, I wrote that as far as I knew there were no useful blends with these modes. Now I know different.

Dan Margulis
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 00:32:55 -0400
   From: Ric Cohn
Subject: Re: Eighteen Questions about Dan's new LAB book

Andrew,

Thanks for posting this. As one of those who have looked at the 16bit/8bit issue in some depth I know how difficult it is to put this information together. I also experienced myself the problems (and some pitfalls) in doing my tests and so wanted to look at yours closely. I'll leave it to others to debate whether this shows a benefit to editing in 16 bits, although I was surprised at how much sharpening separated the 2 files. It certainly shows a difference (although this isn't contested anyway), and I do think the dark greens look better in 16 bits at high magnifications. Here's what I see:

1). Unedited: 8 bit converted w/ & w/out dither preference. Based on your seeing a difference between the unedited 16 and 8 bit files I assume you had dither on. At 1600% I  can see a difference between the two 8 bit files. The 8 bit file converted w/out dither looks virtually identical to the 16 bit file (to my eyes).

2). There is a much bigger difference after editing, of course: @ 400% can see big difference in dark greens. If go back to step before sharpening the difference is more subtle. @ 1600% the difference is more obvious. However, the 16 bit file looks softer. I'm not sure you would sharpen a 16 bit file and an 8 bit file identically if you were looking at both on screen? Surprisingly to me, the sharpening step makes the biggest difference, and going back one step they are more similar.

At 800% looking at just the 16 bit file and the "no dither" 8 bit file, I would say the 16 bit file looks softer, but with more discrete tones. I would say the darkest greens look more "realistic" in the 16 bit file. however the midtones look softer and I would suspect might not look as sharp in a print. At 400% the tones driven darker are very obvious in the 8 bit file. However, as I said the 16 bit file always looks softer. If I do as little as add 2 levels of Threshold the files become much more similar.

3. The image at 240 dpi is only about 2 x 2.3 inches. I doubt any repro method would show a difference. However, I know some people need to interpolate up their digital files. So assuming someone had this image and needed it reproduce it at a reasonable size I upsized 400% using Bicubic Smoother. Here I would say the dark greens would probably look better in a print from the 16 bit file. However, I still think the midtones look sharper (and better) in the 8 bit file. Now we're getting into the area of whether we could do a better looking correction for both files which I think is the real point. There are many unexplored variables in this test. For example, I would not normally consider ProRGB to be a suitable 8 bit editing space. What happens if both files are converted to AdobeRGB before editing? Perhaps I'll look at this later.

I looked up the Canon 350D and I believe it's the Rebel version of the 20D (which I've used). I know it's a very nice camera, but not up to the D1s, which isn't up to the top medium format single shot backs, which aren't quite as good as the 4 shot capture backs (because of uninterpolated color) which probably aren't quite as good as a scanning back (although I don't use these because I believe the limitations aren't worth dealing with except perhaps for museum archiving work). My point being that it's the images that count. If you want to agonize over a few lost bits then go for the best capture to begin with. This reminds me of when I first started to do photography as a hobby. I loved the work I saw that was shot with large format cameras. I wanted to take pictures like that but all I had was a 35mm camera. I shot with slow film on a tripod and processed in fine grain developers. I spent hours in the darkroom working to bring out a widest tonal range I could. My landscapes still looked like shit compared to something shot in 4x5 or 8x10. However, when I stopped trying to make my pictures look like large format and started taking the kinds of pictures that 35mm was suited for my pictures got a lot better. Later when I had a chance to work with large format film I could achieve the results I was looking for.

I'll be interested in hearing other's views.

Ric Cohn
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 00:53:49 -0400
   From: Ric Cohn
Subject: Re: Response to Margulis's answers my 18 Questions about LAB book (now new book)

On Sep 3, 2005, at 7:46 PM, Dan Margulis wrote:

So: for discussion. What *categories of image* would you particularly like to
see treated in the next edition of Professional Photoshop? Also, I'm
comfortable with the format described above, but it isn't set in stone. So, comments
or criticism of it are welcome.

I'm delighted to hear of your plans for the next revise. I too would like to learn more about blending modes. For pure info the book Channel CHOPS is an amazing book, which I'd like to see revised, but it leaves out a lot. I've read everything I can find and am getting a little better, but I still lack an intuitive understanding. Maybe you should take this on!

As far as images go, some of the most amazing blends I've personally witnessed were channel blends for skin tones by an experienced retoucher (who I know took your course although I don't know if they learned this there). I can't reproduce it or get my head around the concepts, but they took blotchy skin tones, did some channel blending and presto it was peachy!

Another area I'd be interested in is images where blending modes added to the 10 channels give even more options for creating natural masks.

BTW, my copy of Canyon is waiting for me at my studio. I can't wait to dig in after the holiday.

Ric Cohn
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 05:08:56 -0000
   From: Stephen Marsh
Subject: Re: Blending Mode Book

Dan, I don't know if you would wish to do a whole book on this topic (it can be done though, once you introduce techniques and practical application, as you have before with blends like lighten/darken).

Some general thoughts on blending modes.

I agree that the old Biedny co-authored book was the 'bible' on blend modes and channel operations, and that with the addition of new blend modes things should be updated. Years ago I had to choose between the CHOPs book and Professional Photoshop, Dan's book won, but only due to the fact that it had wider application for me and the ROI was better on his book.

The problem that an author has, is that Adobe consider many of the blend mode math to be proprietary and or trade secrets and do not give out much deep info to those commenting on the application, even when it could benefit Adobe's customers. Although knowing how things work may be important to some authors or readers, knowing how to use blend modes whith their known properties without knowing the math behind it may be more critical and beneficial to the end user. Adobe does not make this hard, any user with enough education and time can figure it out. Which is the problem for most users, they have enough on their plate as it is. Perhaps those with programming knowledge and a SDK know more than the average commentator.

Although not Photoshop, this blending mode PDF explains some blending modes:

http://www3.sympatico.ca/bryang/chops/

The third PDF is on blend modes, but the other two may be of interest as well. Doing a search on the web will also kick up more info on blending modes.

P.S. I would also like to add that using layer option blend if sliders is similar, but not the same as using layer masks or blend modes like lighten/darken, at least when it comes to USM. Sometimes one is better than the other, or both are similar. One can even combine them. I think that most users would be better off learning blend if sliders before they learn about layer masks.

Stephen Marsh.
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 00:41:15 -0600
   From: Ron Kelly
Subject: blending modes

Here's my viewpont FWIW:

When you devise a method for improving something it happens as a result of a process. What process?

A new insight is gained in how to utilize the lab colorspace. Far more skilled practioners than I have declared it to be revolutionary and I believe in their credentials and their motivation.

I have also seen miracles demonstrated by those who manipulate blending modes. How did they figure this out? Lee Varis knows some of this magic, and so does Dan Margulis, and probably more still.

Some of you on this list will be old enough to remember this anecdote.

There was once a cartoon on television with a character called Foghorn Leghorn (a large chicken full of bluster). In one episode he is entertaining his nephew (an egghead with large glasses) who is a young chicken (let's call him Andrew). Foghorn tells the kid, whom he thinks is a bit wet behind the ears, "Let's play a game of hide-and-seek."

He quickly describes the rules to his nephew and says that he'll hide somewhere, but when Andrew turns his back he hides OUTSIDE the playing field. Foghorn says to the camera, "this'll be good for the kid, and teach him that life ain't fair" (sic).

Next scene: Andrew counts to ten, lifts his head and sees that his uncle has disappeared. Instead of searching for Foghorn he does some furious calculating on paper and pencil (or maybe he uses a slide rule) and then he goes to a spot on the ground which he marks with a big "X". This is NOT the spot that Mr. Leghorn hid in, but when the kid digs  into the ground, sure enough out pops his famous relative. Mr. Leghorn is nonplussed but as he plays to the camera, "what are you going to do?"

It seems to me that those on the inside track on blending modes and lab magic are using those same slide rules. Where can you get one?

I'm identifying more with Mr. Leghorn at the moment.

Ron Kelly
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 13:14:47 +0200
   From: "Francisco Bernal"
Subject: Re: Eighteen Questions about Dan's new LAB book

Prhophoto is a space excesivaly big to be usefull ¿Don't you think so? It has far more number for colors than usefull colors, so the actual amount of "numbers" you can "assign to real colors" is prerttysmall. Wide gamut spaces are so unpractical!!

/*--------------------------------------*/
"If quality is important, sRGB is not an option"
(From the European Color Initiative web page www.eci.org)

Francisco Bernal Rosso

Luz-color-fotografia
Redacción y traducción
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 08:39:58 -0500
   From: "Mike Davis"
Subject: RE: Professional Photoshop 5th Ed.?

I don't envy Dan one bit (no pun intended) on his dilemma.  The problem would seem to be how to define the market and provide for it.

Do you cave in to time pressure from the publisher as a result of a far greater sales response to "LAB" than was anticipated, or do you cater to the needs and desires of the buying public and turn out another landmark book on advanced image work, which takes time?  That, in turn, begs the question as to what those desires are, and how big is that increasingly limited market, how long will it wait, and who is poised and able to trump the effort?  

Frankly, I am stunned (and delighted) by the response to "LAB".  What we don't need is yet another Photoshop book on using the tools and putting gorilla heads on giraffes. I'd begin by finding out who is buying "LAB".

The "LAB" book is hard to categorize.  "Channel Chops" is a similar work. Both might be said to be vertical topics, however the techniques can be applied to many types of images and output intent, hence spreading horizontally for color (and B&W retouchers), and serious hobbyists whose numbers are increasing with the explosion in digital camera sales.

So what do we need, and what will pay its own way?  I'd suggest looking at new additions to Photoshop and how they integrate into advanced workflow from a professional perspective, not just from a brief overview:

Blending modes are a weakly understood topic, and, as a specialty topic, not thoroughly addressed outside of the classic "Channel Chops" book of seven years ago, now largely unavailable and somewhat outdated.  "LAB" has some excellent advanced chapters on using blending modes, but there are 22 of them now, some of value, others perhaps largely ignored in the various color spaces.

The various blurring filters, their uses and disadvantages from a pixel, blending and masking perspective (Dan touched on the new Surface blur, which I would have ignored).

Creative uses and effects of the various noise filters including the new Reduce Noise or alternatives in masking and blending.

Sharpening revisited in light of the many traditional alternatives and in comparison with the new Smart Sharpen/Lens Blur/Gaussian Blur and Shadow/Highlight tools.

Camera RAW from the Margulis perspective would be interesting.

Creative B&W work might include unique ideas different from routine grayscale handling of color plates (I recall mention of an older book by Jim Rich & Sandy Bozek called "Photoshop in Black & White" by Peachpit Press which I've never seen).

Re-visit topics from Channel Chops to fill a hole left by this publication.

And as Dan mentioned, look for problems unique to advanced amateurs with digital capture devices including color balance problems stemming from improper camera settings (grabbing a camera for a quick shot without time to set up, such as AWB and JPEG issues) and dye shifts in transparency scans, some of which can be extremely challenging to balance properly.

Ultimately, a book aimed at pre-press pros is targeting a dwindling market. I would suggest a continued update of "Professional Photoshop" but with the needs of the serious amateur digital photographer firmly in the crosshairs, and a new title for the bookshelf browsers.  Titles like "Professional Photoshop", in my mind, don't attract the casual browser in a large bookstore.  I recall overlooking it several times a few years ago and finally stumbled over it when I heard someone else talking about it.  The sub-title "Classic Guide to Color Correction" would have attracted my attention, but it wasn't on the spine of the book and I never pulled it off the shelf to see it until quite later.  I wasn't a "pro" and I'm still not. Even if I had not been lurking here as a fan of Dan's, the title "Photoshop LAB Color" would have instantly grabbed me because it is unique.

Mike Davis
mldavis2 AT sbcglobal DOT net
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 10:12:00 -0400
   From: Iliah Borg
Subject: Re: Professional Photoshop 5th Ed.?

On Sun, 4 Sep 2005 08:39:58 -0500
 "Mike Davis" wrote:

I would suggest a continued update of "Professional
Photoshop" but with the
needs of the serious amateur digital photographer firmly
in the crosshairs,

Serious amature digital photographer... Can you characterise this person? How many of those are prepared to spend hours and months to study postprocessing, instead of shooting? The whole point of migration to digital for many is getting their images out fast, and in JPEGs. Camera settings to get best quality are most discussed things, up to such as should white balance be on Auto-3 or Auto+2.

Not that I'm saying that such a book will be useless or unprofitable, it is just that too many things out of the scope of post-processing should be covered, too many different camera makes/models make difference in post-processing, and ACR is not always what a Nikon shooter (for example) needs.

Add to this weired design decisions camera makers are implementing, like pairing tonal mapping with colour space, or blurring/sharpening raw data right in the camera. I'm afraid it is too easy targeting this very interesting market to come out with an "ordinary" tips and tricks book, which will be one of many.

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 08:55:39 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/3/05 10:32 PM, "Ric Cohn"  wrote:

1). Unedited: 8 bit converted w/ & w/out dither preference. Based on
your seeing a difference between the unedited 16 and 8 bit files I
assume you had dither on.

Dither is used for color space conversions which can be turned on or off in color settings and only affects 8-bit data.  I did no color conversions. The file went from RAW to ProPhoto RGB in ACR. You might want to try converting after the edits on both to some output color space to see if things in 8-bit get even worse.

At 1600% I  can see a difference between the
two 8 bit files. The 8 bit file converted w/out dither looks virtually
identical to the 16 bit file (to my eyes).

Strange effect I've never noticed before. While this looks like dither is introduced, it's not the same as above and unless Adobe is doing something as they convert to 8-bit, I'm at a loss to explain it. But you can see it when you toggle between the two bit depths at 1600%.

However, the 16 bit file looks softer.

The effect of the aliasing (which is not good) produces the appearance of sharpness due to the increase in contrast. But this isn't something we want! I have similar captured files where I see this in dark gray clouds and it's pretty ugly. This isn't a contrast of edges as we'd see in typical USM, it's banding that is somewhat uncontrollable and affected by tone (and I suspect some colors as well). Take an unsharpened file, use the Add Noise filter and I'll bet it appears a bit sharper. I don't know anyone advocating the use of noise to make images look sharper <g>

I'm not sure you
would sharpen a 16 bit file and an 8 bit file identically if you were
looking at both on screen? Surprisingly to me, the sharpening step
makes the biggest difference, and going back one step they are more
similar.

In this case no because sharpening would make the noise even more visible. This is why the discussion of using masks from the image itself to sharpen was something I raised before. ANY global sharpening no matter the color mode is pretty discriminant. An image mask can hold back sharpening in smooth areas or dark areas like the one's we are seeing that have noise. The noise is there in 8-bit far more than 16-bit which is the issue. At this point, sharpening should be conducted on either or both with the utmost control. Using a true Grayscale image mask made from the image can accomplish this.

At 800% looking at just the 16 bit file and the "no dither" 8 bit file,
I would say the 16 bit file looks softer, but with more discrete tones.

Exactly. That's what I'm seeing. That explains why the 8-bit looks "sharper" and why it's a problem because subtle continuous tone is now going away. What happens when we use other edits or convert to an output color space? Compounded issues are possible and the reason proponents of high bit editing exist! We don't know how much worse this will all get down the line.

The image at 240 dpi is only about 2 x 2.3 inches. I doubt any repro
method would show a difference. However, I know some people need to
interpolate up their digital files.

...or further edit the file, output to a high rez, continuous tone device and so forth. Bottom line is, the high bit file has more editing potential. Something Bruce mentions in his book.

I looked up the Canon 350D and I believe it's the Rebel version of the
20D (which I've used).

More or less yes. The CMOS chip may be a bit newer but its the same size. The processing may be different too. They should be pretty close. Yes, there are substantially better quality digital capture devices which may show the benefits of high bit more (or not). Keep in mind that only 3-4 years ago, this was state of the art in DSLR technology.

Andrew Rodney
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 08:56:02 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/4/05 5:14 AM, "Francisco Bernal"  wrote:

Prophoto is a space excesivaly big to be usefull

It1s very useful if you want to contain colors your capture device (in this case my Canon) is able to capture. I can provide many images that fall outside of Adobe RGB (1998) that are fully contained in ProPhoto RGB. I can also show you output devices (the new Epson 2400 at a mere $800 is one) that can reproduce colors that fall outside Adobe RGB (1998) but are fully contained in ProPhoto RGB.

There are no prefect working spaces or we1d only need one! The advantage of bigger spaces is holding onto colors we can capture and ultimately reproduce. To do this, we need in big honking gamut spaces to hold colors that fall outside the simple shapes of all working  spaces. All RGB working space are synthetic constructions and have simple shapes, especially compared to output color spaces. If you want to hold all the captured colors you can possibly output (even to a device made in 2005), you need a really big working space shape and ProPhoto fits the bill. Just do the editing in high bit, the point of this discussion.

Andrew Rodney
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 12:47:35 -0400
   From: Iliah Borg
Subject: Re: Blending Mode Book

To be published this November , btw:

"Photoshop Blending Modes Cookbook for Digital Photographers: 48 Easy-to-Follow Recipes to Fix Problem Photos and Create Amazing Effects"

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 09:49:48 -0700
   From: Lee Varis
Subject: Re: Eighteen Questions about Dan's new LAB book

On Sep 4, 2005, at 7:56 AM, Andrew Rodney wrote:

It's very useful if you want to contain colors your capture device (in this
case my Canon) is able to capture. I can provide many images that fall
outside of Adobe RGB (1998) that are fully contained in ProPhoto RGB. I can
also show you output devices (the new Epson 2400 at a mere $800 is one) that
can reproduce colors that fall outside Adobe RGB (1998) but are fully
contained in ProPhoto RGB.

Unfortunately ProPhoto RGB is like using a sledge hammer to drive finishing nails. Besides, all this discussion about containing very saturated colors is a little bit like talking about how many angels fit on the head of a pin.

Everybody is obsessing over a small subset of very saturated colors!

For the most part we should be more concerned with color relationships and tonal compression. Until we have high dynamic range backlit displays being used for final output, images printed on paper should be our primary concern. Images printed on paper are evaluated in the context of that paper! Making images that have a range of tones and colors that look good to a human observer does not require working in ProPhoto RGB or 16bits. Advocates of wide gamut/high bit color spaces always end up talking about real colors that you could capture and "contain" - humans respond much more to contrast than color. Color contrast is more important than color gamut or hue. Wasting data by spreading it out in a huge erratically shaped color space just to "hit" a saturated color that falls well outside of an editing environment seems to me to be counter productive because it does nothing to make it easier to work within the constraints of fairly small output spaces.

I've never seen anyone complain about the colors of a Lightjet photographic print yet the Lightjet has a color gamut slightly smaller than sRGB!

We're not trying to "contain" color but to translate it so that it works in a completely different context.

To that end the only thing I find "useful" about ProPhoto RGB are the individual channels for the purpose of B+W conversions and luminosity blending NOT color "containment". Having a huge color space helps to render grayscale channels with more tonal detail (avoids clipping highlight and shadow detail in saturated colors) and this tonal detail IS more easily manipulated for grayscale images and luminosity blending techniques into smaller color workspaces. The ProPhoto grayscale channels CAN be brought into 8bit very successfully when you're not concerned with color!

So the best thing about ProPhoto RGB is grayscale imaging not color!

regards,

Lee Varis
http://www.varis.com
888-964-0024
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 13:08:07 -0400
   From: Iliah Borg
Subject: Re: Eighteen Questions about Dan's new LAB book

On Sun, 4 Sep 2005 09:49:48 -0700 Lee Varis wrote:

So the best thing about ProPhoto RGB is grayscale imaging
not color!

Dear Lee, have you tried taking images of flowers, red roses, for example?

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 13:15:04 -0400
   From: "Gene Palmiter"
Subject: Re: Blending Mode Book

This is interesting...but what I want is not recipes but an understanding of how things work...then I can create my own recipes. I don't want to be a cook but a chef.

Thanks,
Gene Palmiter
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 13:21:51 -0400
   From: Iliah Borg
Subject: Re: Blending Mode Book

GIMP and ImageMagick are available in source code, and include blending. You can also look at Kostia Vasserman's project of image blender, coded in Delphi, as far as I remember.

O'Reilly's book includes explanations on the math behind nlending, too.

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 11:48:23 -0600
   From: Andrew Rodney
Subject: Re: Eighteen Questions about Dan's new LAB book

On 9/4/05 10:49 AM, "Lee Varis"  wrote:

Unfortunately ProPhoto RGB is like using a sledge hammer to drive
finishing nails. Besides, all this discussion about containing very
saturated colors is a little bit like talking about how many angels
fit on the head of a pin.

Sorry Lee but that's just silly talk. Surely you have RAW digital files you can examine in ACR to show you saturated colors captured that fall outside Adobe RGB (1998) but could and can be output on an $800 ink jet printer among others. If you want such RAW files from a lowly $900 Canon 350 Rebel let me know.

Everybody is obsessing over a small subset of very saturated colors!

That's like saying a photographer who prefers the look of Velvia is obsessing over saturated colors that can't be produced on Ekatchrome. Are you really proposing that? Because I think I can fill a room at PhotoPlus Expo with shooters who would gladly obsess over that added saturation in a chrome they can't possibly place on a four color press (but might on a Ciba). Digital capture can represent a far wider color gamut than any E-6 film.

For the most part we should be more concerned with color
relationships and tonal compression. Until we have high dynamic range
backlit displays being used for final output, images printed on paper
should be our primary concern.

I need all the colors to DECIDE what to compress. If you throw them away from the start, I can't do that.

Images printed on paper are evaluated
in the context of that paper! Making images that have a range of
tones and colors that look good to a human observer does not require
working in ProPhoto RGB or 16bits.

No but at this point, I have the option of containing the colors or throwing them away forever. In ProPhoto, I can decide today or in the future how I want to hand out those colors. In Adobe RGB (1998) it's gone. Yes I can go back to my RAW file but that's akin to going back to my color negative and making another custom print, spotting it and so forth. Why do this twice?

Wasting data by spreading it out in a huge erratically shaped color
space just to "hit" a saturated color that falls well outside of an
editing environment seems to me to be counter productive because it
does nothing to make it easier to work within the constraints of
fairly small output spaces.

There's no waste. Throwing away the color is a waste. It's not erratically shaped. It's shaped this way for a very good reason. My proposition in photo centric terms is, if you shoot an 8x10, it's silly to now process the image and take scissors to the it and crop it down to 4x5.

I've never seen anyone complain about the colors of a Lightjet
photographic print yet the Lightjet has a color gamut slightly
smaller than sRGB!

And you did this with a ProPhoto RGB image as well with a scene that contained data outside of sRGB? If not, I can fully understand why no one would complain. Talk about imagery colors!

And Lee, whatever profile you used to compare the Lightjet to sRGB is crap. It's absolutely not smaller.  I have profiles made for a Lightjet at Pictopia. There's quite a nice slice of many colors that fall outside sRGB like yellows, greens and magentas. Less so in Adobe RGB (1998) but even with that color space, the Lightjet produces colors outside it's gamut (yellow and magenta).

We're not trying to "contain" color but to translate it so that it
works in a completely different context.

If you can't contain them, you can't use them or translate them.

Andrew Rodney
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 14:20:23 -0400
   From: "Gene Palmiter"
Subject: Re: Blending Mode Book

To take the analogy further....source code is like the genetic code that defines wheat. That won't feed me either! What got this conversation started was a desire, shared by others as I recall, that while we had books that told us what the blending modes did...we had nothing that gave us the ideas that let to the blending modes so that we could decide which ones might be helpful in a situation. The programming code won't do that.

People who like Professional Photoshop, I suspect, already have several other books on their shelves. I have the Bibles, and Kelby's Photoshop book and several others. Dan's book falls between these. Its less than a general reference and more than a step-by-step how-to. Its a detailed exploration of a specific subject. I think what we are asking for is something like that for blending modes. Something that we could read over once and use as a reference forever. Step-by-step books are ok...when I need something specific I can go and refresh my memory...but if I know the ideas behind it I can go further.

Thanks,
Gene Palmiter
(visit my photo gallery at http: //palmiter.dotphoto.com)
freebridge design group
www.route611.com & Route 611 Magazine
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 11:47:48 -0700
   From: Marco Ugolini
Subject: Re: Professional Photoshop 5th Ed.?

In a message dated Sun, 04 Sep 2005 10:12:00, Iliah Borg wrote:

The whole point of migration to digital for many is getting their images out
fast, and in JPEGs.

I certainly hope that this is not "the whole point" of migrating to digital for everybody. A long time ago and far away, I used to print B&W photography in the darkroom for a living. My purpose for switching to digital to print my own work is not just "to get my images out and fast," though the increased speed is attractive, no doubts about it. I care just as much, perhaps more, about how much control I have now over the QUALITY of my output, and I am sure that many others feel the same way.

--------------
Marco Ugolini
Mill Valley, CA
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 12:58:39 -0600
   From: Andrew Rodney
Subject: Eighteen Questions about Dan's new LAB book (16-bit challenge)

On 9/3/05 7:02 PM, "Dan Margulis"  wrote:

I will probably take you up on the
offer to provide the raw file, provided you are willing to give me permission
to publish it.

I1ve uploaded this RAW file (CRW_0775.CRW) to the same location as the other files (I1ve over-written the original ZIP archive and it is now 9.5mb). The ZIP archive still contains all the other files in addition to this RAW file and the XMP data used to define it in ACR (you should be able to import this to set my ACR settings on this RAW or simply turn everything off there). The full image isn1t quite as ugly in total (it1s a shot of my new office being constructed). I still want to shoot other scenes but this should do for the time being.

To download:

http://www.digitaldog.net/files/16bitchallange.zip

The other interesting item is while this doesn1t at all appear to be a scene containing saturated colors, in ACR, I do see clipping when I set the output color space to Adobe RGB (1998) but not ProPhoto RGB. You1ll see that there1s a pretty large blue clip on the far left of the histogram in Adobe RGB (1998), none when you toggle to ProPhoto RGB. This is the yellow flowers in the foreground. The camera is rendering the RAW file such that these colors are outside the gamut of Adobe RGB (1998).

An interesting exercise in this respect can be seen using the new crop tool. Crop a small area of the total image (say 25%), move it around from the yellow flowers to the blue sky as you toggle the various color spaces while viewing the histogram. A solid color clipping will show the complementary color falling out of gamut. White would be full clipping (all three color channels). Lower the saturation slider and see how the fully saturated colors that clip are affected. Another poster asked of Lee 3do you shoot flower2? This isn1t by any stretch of the imagination a scene one would say has bright, saturated colors and yet, if the goal is to at the very least contain and possibly use colors captured, encoding into Adobe RGB (1998) would clip our yellow flowers.

Then next logical question would be, can you use those yellow colors? The answer is, it depends. I converted the RAW in both Adobe RGB (1998) and ProPhoto and using ColorThink, I can actually plot the colors of an actual image on top of the gamut of an output device. Very cool feature. Anyway, using my Epson 2400, there1s a significantly larger amount of yellow I can actually use from the ProPhoto file. I1ve placed a screen capture in the Zip archive. You1re seeing the gamut of the Epson 2400 in actual color. In the bottom you can see the yellows. The red dots are the gamut of the image (cropped to just flowers) in Adobe RGB (1998). The green is the same image but in ProPhoto RGB. You1ll see there ARE yellow colors that fall outside the printer gamut. Yet  far more greens dots (ProPhoto RGB) fall within gamut compared to Adobe RGB (1998) which can1t hold colors that the wider gamut file can use for output.

If the yellow in this image isn1t important to you, then neither is the use of ProPhoto. However, if the yellow (and other colors) are important, the output device can use them with the wider gamut color space. You can also see the amount of yellow gamut we would throw away by going directly to Adobe RGB (1998) instead of simply holding onto them by using ProPhoto RGB.

Enough color theory, time to grill burgers.

Andrew Rodney
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 18:15:09 -0400
   From: Denton Taylor
Subject: Re: Professional Photoshop 5th Ed.?

Take out the word 'digital' and then ask yourself how many of us started fooling around with photography before getting hooked?

THe majority of folk just want to take nice Christmas pictures of the family. (At least now they can easily get the redeye out!) Some subset of those began to really like photography. In the past they might have joined a camera club, taken a class or two on the darkroom, and so on.

Add back the word 'digital' and subtract the darkroom while adding in PhotoShop.

One problem is that us old-timers cut our teeth on manual cameras, so we learned about DOF, exposure compensation, spot metering, the zone system, and so on. We can make the necessary adjustments when automation fails.

It's really hard to manually focus a $500 digicam. It's really hard to do an exposure comp. I can do it because I know that I need these features and when I buy a camera (my carry-around camera is a 7mpx Canon G6) I look for them.

Currently I'm helping a friend of mine, who had a cheap film auto-everything SLR and a shoe-mounted flash. He does OK financially so he 'upgraded' to a Nikon 8mpx camera, I forget the model. He's practically in tears cuz he cannot get any good results. He has faithfully read the manual and uses the pre-sets (wedding, portrait, group, and so on) religiously. Of course none of them really work as advertised, so his photos have been coming out much worse than when he shot film. What he really likes is indoor family stuff, weddings, and such. As we know, that's trickier than it seems.

The first step is that I got him to buy an external flash. Then I got him to shoot everything in program mode. Things are much improved.

Next I'll be working with him to switch to RAW from JPG.

So, there really is a market for a book, maybe a series of books, that can lead a interested photog thru these hurdles. The only thing that will change in the technology is more mpx, right? jpg and RAW will be around a while...

Ansel Adams did a similar series, right?

Regards,

Denton Taylor
photogallery at
www.dentontaylor.com
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 20:41:49 EDT
   From: Dan Margulis
Subject: Re: WB in Lab

Iliah writes,

As you see, the file balanced in RGB shows different tints
in shadows and highlights, and only the point it is
balanced in is really neutral; while file balanced in Lab
(which is linear space) maintains neutrality across the
gradient."

LAB definitely is the space of choice to take out mild overall casts. However, if the cast varies with the darkness of the image, RGB or CMYK is more effective--in LAB you would need a mask. And, nowadays digicams give us the abomination of images that are neutrally correct in both highlyts and shadows and heavily cast in the midtone, which calls for a more flexible approach.

But yes, if that were a real image of neutral jewelry, say, rather than a computer-generated gradient, it would be harder to fix in RGB than in either CMYK or LAB.

Dan Margulis
____________________________________________________________________________

   Date: Sun, 04 Sep 2005 21:08:27 -0400
   From: Iliah Borg
Subject: Re: WB in Lab

Dear Dan,

Thank you.

On a different note, the problem with colour casts in many digital cameras can be attributed to RAW processing, including internal. As I deal with RAW images, I see that black and white points are forced in processing, while overall gamma correction to bring image to visually pleasing is done using old NTSC to Luma formula (or, generally, linear transforms using RGB weights). It is similar to using composite curve, which introduces colour disbalance.

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 20:05:14 -0700
   From: Lee Varis
Subject: Re: Eighteen Questions about Dan's new LAB book

On Sep 4, 2005, at 10:08 AM, Iliah Borg wrote:

Dear Lee, have you tried taking images of flowers, red
roses, for example?

Yes.

regards,

Lee Varis
http://www.varis.com
888-964-0024
____________________________________________________________________________

   Date: Sun, 4 Sep 2005 20:19:28 -0700
   From: Lee Varis
Subject: Re: Eighteen Questions about Dan's new LAB book

On Sep 4, 2005, at 10:48 AM, Andrew Rodney wrote:

Sorry Lee but that's just silly talk.

I'm not going to respond to any more of your objections as you pointedly refuse to understand the points I'm making and instead reiterate your first and only rant about color gamut, throwing away colors, etc... We get it... we've all heard this time and time again - someday sometime in the future it might mean something - right now I've got work to do getting some images to look good on a piece of paper. Don't worry, I'm holding on to my raw files though I expect that the carefully crafted prints I'm saving for my grandkids will be worth more money 30 years from now when they're considered collectable because they are done using some antique process by the original artist!

Over and out!

regards,

Lee Varis
http://www.varis.com
888-964-0024
____________________________________________________________________________

From: Werner Tschan
Date: MonÊSepÊ5,Ê2005Ê 4:53 am
Subject: Re: [colortheory] Eighteen Questions about Dan's new LAB book

Andrew Rodney wrote:

So you agree that there's some advantage of high bit editing, all
corrections being equal? I suspect the forum host doesn't agree with that or
at least, has been asking for side by side comparisons. I don't recall the
working space being part of this challenge.

I've been following this forums discussions about bit depth for some time. I am gald that after all you found one situation that proofs you right. I have great respect for your knowledge, only, I wonder where you guys take the time to go through such length to prove your (religious) beliefs.

Thanks anyway for the entertainment you offer to the readers of the list! I have to stop here. Got to correct 63 files for print until this afternoon. I guess I'll go for 8 bit this time...

Werner Tschan
____________________________________________________________________________

From: "Mike Davis"  
Date: MonÊSepÊ5,Ê2005Ê 1:51 am
Subject: Re: Professional Photoshop 5th Ed.?

"Serious amateur photographer". Egads, who knows? My suggestion was to find out who was buying "LAB". There must be thousands of people like me who are "serious amateurs" with decent (not professional) equipment, who buy libraries of Photoshop books and read them all page by page hoping to glean manna from each one.

I shoot a lowly Canon 20D with only 3 lenses, and print on a cheapo Epson Photo 785EPX printer. Anything larger than 8x10 goes out for printing, and I post many of my images on PBase.com just for fun. Many of those are being re-processed in light of my learning curve.

It would be a total waste for someone of Dan's credentials to write a "how to" book rather than a "why" book. I suspect only Dan can put together an update that would include things that the rest of us wouldn't dream of, so perhaps he's on his own. But whatever it is or says, I'll buy it unless it begins by describing the tools pallet.

My own use of Photoshop outside of personal hobby work is as a forensic scientist (yeah, a real CSI). Many times my task is to edit a digital capture (scanner or camera) in order to enhance certain items for better visibility. A common example is to remove background half tone dots on a forged check to better view a fingerprint developed in ninhydrin which forms a violet image. No one has written specifically about doing such things, but my understanding of blending modes, masks and color charts allows me to devise ways to doing this, almost the opposite of obtaining a correctly balanced image.

For many hobbyists, Photoshop, at $699 a copy, is a serious purchasing decision. No big deal for the pro who writes it off as a business expense, but a big deal to many hobbyists. As a scientist trying to understand the whys so I can create my own hows, the pedantic but entertaining work that Dan does is a must on the bookshelf.

The answer to what a "serious amateur" is will not be easy or obvious, or Dan would not have asked for feedback on the update. I suspect that only a small percentage of amateur photo hacks are disciplined or interested enough to plow through "Professional Photoshop" or "LAB", but they are obviously coming from somewhere. My only caution was to re-adjust sights a bit and encompass this quickly growing group. If the book does not appeal to a large segment of the digital imaging market, there won't be many more books. That doesn't mean "dumbing down" the material, but it should include sufficient new material to attract this larger, evolving market.

Mike Davis
mldavis2 AT sbcglobal DOT net
____________________________________________________________________________

From: Ric Cohn
Date: MonÊSepÊ5,Ê2005Ê 12:30 pm
Subject: Re: [colortheory] Eighteen Questions about Dan's new LAB book

On Sep 4, 2005, at 10:55 AM, Andrew Rodney wrote:

Dither is used for color space conversions which can be turned on or off in
color settings and only affects 8-bit data. I did no color conversions. The
file went from RAW to ProPhoto RGB in ACR. You might want to try converting
after the edits on both to some output color space to see if things in 8-bit
get even worse.

Indeed the preference does say it's for 8 bit transforms, but my experience and my results suggest that Photoshop applies the dither in the 16 bit to 8 bit conversion if this preference is checked. I'd say this behavior should at least be acknowledged. It's not always bad as I personally experienced the advantages in reducing banding when I did my 16 Bit vs. 8 Bit comparison a few years ago.

Take an unsharpened file, use the Add Noise filter and I'll bet it appears a bit sharper. I don't know anyone advocating the use of noise to make images look sharper <g>

Not sharper per se, but I sometimes add noise to my digital captures. I frequently find that the digital captures smoothness (I'd say Unnatural smoothness) rather ugly. I like variations and imperfections and believe that a smooth histogram can be a sign of trouble, but not in the way that those that hate gaps mean. What would be interesting to me would be to look at the histograms of images (both paintings and photographs) I find beautiful or emotionally affecting. I remember a similar study of music tonal variations from my college days that was very revealing.

Ric Cohn
___________________________________________________________________________

From: "R. Lutz"
Date: MonÊSepÊ5,Ê2005Ê 4:14 pm
Subject: Re: [colortheory] Re: Professional Photoshop 5th Ed.?

Dan, The last time I wondered through a book store I remember thinking the shelves were saturated with books about Photoshop. Marketing success seems to require that they use an endless repetition of the words professional, creative, and secret. Why not name it [tongue in cheek] The Ten Secrets to Being a Creative Professional in Photoshop (if is hasn't already been used).

I think Mike Davis gave a clue to an important group of Photoshop users that might warrant at least a chapter in a new Photoshop book. Scientists of all sorts have difficult imaging problems. Whether it is getting better detail from a ninhydrin stained fingerprint or as someone asked a month or so ago, how to get a better color separation between a background green and the green of a florescent label on a tissue specimen. Many microscopists (light, and electron) need help improving the images they publish in scientific journals. And the journal printers don't seem to know what to do either. While there are certainly some good images in scientific journals, for some of them it is less than the norm. Good image handling is important in chromatography, electrophoresis, tomography, and more scientific tools than I know to mention. Some of the images may be derived by exotic means but they still have to be prepared for publication. They need to know the same techniques that you teach to photographers and printers; and I think, if you would add a little information about the scientific techniques, you would add value not found in other Photoshop books. I'm not sure how broad the appeal would be, but a chapter of this sort would catch my interest.

Iliah Borg's list of common digital problems and their cures should catch the interest of the new digital photographers that you will want to add to your readership.

Dan, Since everyone seems to comment on the first half of your LAB book, let me say the last half is even better. I particular liked your inventive use of an RGB version of a file to make a new L channel for working in LAB, and the clever use of A and B channels to add tonal detail to an image.

R. Lutz
____________________________________________________________________________

From: "Raymond E. McKinley"  
Date: MonÊSepÊ5,Ê2005Ê 7:06 pm
Subject: Eighteen Questions

Dan writes

Also, I'mcomfortable with the format described above, but it isn't set in stone. So, comments or criticism of it are welcome.

Dan,

I am not clear about the direction that the next edition of Professional Photoshop will be taking. Are you saying that you will be departing from your usual practice of introducing at least 50% new content? Or will the focus of the book be presenting the existing material in a more accessible way, since so much advanced material was presented in the LAB book. If so then you could have your books mirror your classes. I always had the impression that the material in Professional Photoshop was what was covered in your first course.
 
I think you could do an advanced book on channel blending in about another 2 years after readers have had time to digest the material in the LAB book and explore some of the new ideas presented here. Your books consistently raise the bar on what it is possible to do in Photshop and so I think you should continue with this strategy,so far I have only reached Chapter 8 in the new book,I've gotten the most out of the presentation of the blend-if sliders,I have been grappling with them from time to time,since you have so many examples in this book I should be able to finally get a handle on them. Thanks for including the picture of the woman in green with her clothing being changed to a PMS color. I tried doing this when you published the Electronic Publishing article " I think it might look better in red" but now that the images are available it should be easier to figure it out.

I've peeked at the rest of the book and already found a big workflow improvement. I've been experimenting with LAB, but it has largely been groping in the dark. I've been doing blending to enhance detail but suffering with color shifts. The solution in the contrast and color chapter solved this problem. Simply shifting the detail to the L channel and replacing the L channel of a duplicate image took care of this problem. I am sure more answers like this lie in the book.

Regards

Raymond
____________________________________________________________________________

   Date: Tue, 06 Sep 2005 07:22:47 -0400
   From: Iliah Borg
Subject: responce

After reading the column "The Man from Mars Method":

"I tried it on a few of my images and the difference is crazy... it really brings out the colours and makes the images pop using just this one technique... I suspect I've barely touched upon Lab but this has made a real difference. Is this the kind of Lab technique you are talking about... this is just the adjustment curves layer fiddling with a and b channels etc? I'm quite happy!"

Best regards,
ib
____________________________________________________________________________

   Date: Tue, 6 Sep 2005 07:25:57 -0700 (PDT)
   From: JR
Subject: future layout

Dan, I would like to see in a future Photoshop book of your's or someone's:

1. A. The image before and B. Image after corx. 2. Tight/brief clearly numbered steps to achieve. 3. Brief explaination of your reason for choosing a specific direction for attacking the problem.

Baba, my problem I have not resolved in reading your work is how to put all the tools together for a specific result on a specific image in the least amount of time.

If I understand channel blending, if I think I understand why LAB is valuable, if I understand RGB and CMYK, what I really need is the ability to put it all together so I can quickly improve an image in a production environment. I don't have time to try all kinds of mode conversions to see what is there and isn't.

Being a creative color master of which I feel blessed to read your thoughts, I just wish I didn't have to read about Cyrano, and just give the facts, as in: What is the drop-dead, fastest way to bring this image to life and briefly why?

It shouldn't have to be this complex to decide which tools to use on given images and how to do it quickly, or maybe all the different ways are just too much for my wee brain and your books are for special paid individuals. But since digital cameras make adjustments for most people now anyways, how necessary are the individuals who grasp the techniques anyways?

I've seen Photoshop List post after post of folk's talk about how they do not recall beforehand the effect of a layer mode. They go through EACH MODE quickly to see the effects till one looks best. I had wished reading the articles and books on your work would keep me from doing this with channel blending, etc., but not yet. I am much improved as to stopping color casts, hilite, midtone, shadow curve adjustment, even simple channel blending, but I'm still not there yet, and wish for a simpler mode of attack.

For me it's the last battleground, the WHY?

John Robinson
____________________________________________________________________________

   Date: Tue, 6 Sep 2005 10:00:40 -0500
   From: "Sabo, Lori"
Subject: Re: You're Number One

Dan,

I haven't worked past the first chapter yet, but even that is enough to provide a powerful new capability for Lab novices for certain types of images, something that is difficult to do well otherwise.  

My husband has been working through the book and he's said this changes everything.  A lot of specific frustrating images came to his mind that he should have used one of the Lab techniques on as the first step. Especially for fine art repro (giclee) but also for his own photography. He rarely used Lab before.  He found the progression of the book to be very good in terms of getting the basics down easily and then being able to progress to further understanding.  He thought anyone who had a good understanding of what goes on with curves would benefit from the book. I must tell you this is the first Photoshop book I have actually been able to get him to READ all the way through.  He browsed your Professional Photoshop and picked up some things, but skipped over a lot.  This book he is all into.  He does think you go over the top a little once in a while in making some assertions  ;-)

It did seem to me that it would be a good idea to work through each chapter once, and then reread it again later -- makes it easier to catch some of the important fine points.

Lori Sabo
____________________________________________________________________________

   Date: Tue, 6 Sep 2005 10:23:53 -0500
   From: "Sabo, Lori"
Subject: Professional Photoshop

Dan,

The format change sounds great.  I did find the Lab book presentation easier to work through.  (BTW I for one would love to buy a whole book on sharpening at least)  I am sure that you would cover at least some fine art repro images where certain colors (but not all of the colors) need correction because the camera/scanner does not respond as your eye does.  This is true for photos too, but of course less obvious since you don't  have the original scene sitting there to compare the print to.

I think you also need to cover photography strongly -- amazing how many photographers there are these days printing their own work for art fairs, galleries, etc.  With digital technology and the affordable Epson printers, there is a glut of people jumping into photography and printing thereof.  And many doing it just for their own personal satisfaction, as well.  Please consider nuances of preparing for print one of the pro Epsons (or even desktop) vs litho press.

The biggest failing I see with photographers doing their own printing is in the sharpening process . . .

Lori Sabo
____________________________________________________________________________

   Date: Tue, 06 Sep 2005 09:58:59 -0600
   From: Andrew Rodney
Subject: Re: future layout

On 9/6/05 8:25 AM, "JR"  wrote:

Being a creative color master of which I feel
blessed to read your thoughts, I just wish I
didn't have to read about Cyrano, and just give
the facts, as in: What is the drop-dead, fastest
way to bring this image to life and briefly why?

Agreed. Perhaps step-by-step illustrated tutorials?

Andrew Rodney
____________________________________________________________________________

   Date: Tue, 06 Sep 2005 16:21:46 -0000
   From: "dbernaerdt"
Subject: Re: future layout

On the other side this coin, I find that a great many books on software are dry and provide recipes, rather than education. They leave you with the information on how to fix that particular image, rather than the knowledge of when and how to apply the technique. Personally, I think Dan's analogies provide a very interesting illustration that go beyond screenshots.

Darren Bernaerdt
____________________________________________________________________________

   Date: Tue, 6 Sep 2005 11:52:42 -0600
   From: Ron Kelly
Subject: Re: Re: future layout

I agree.

Dan's work is fun to read, usually. I appreciate the philosophy of an approach as much as the exact method. I think it leads to a more complete understanding, which is what I am interested in.

It also helps to differentiate Dan's approach from others of a different philosophy because you understand something about where he's coming from.

Ron Kelly
____________________________________________________________________________

   Date: Tue, 06 Sep 2005 21:27:35 +0200
   From: Werner Tschan
Subject: Re: Re: future layout

I totally agree. Reading Dan's books is like having a good friend  next to you, and not a machine.
I never had more fun reading  technical oriented books. I love Dan's sense of humour.

Werner Tschan
____________________________________________________________________________

   Date: Wed, 07 Sep 2005 17:41:38 -0400
   From: Ric Cohn
Subject: Ideal 8 bit working space?

Thanks to Andrew's test pointing out the dangers of wide gamut working spaces when working in 8 bits, I've been thinking again about which space is best for working in 8 bits. I'm interested in containing enough color gamut for any existing process without getting any bigger than needed. Since very little of my work is high croma with super saturated colors I don't buy into the "capture everything and stay in 16 bit" argument. IMO AdobeRGB is OK, but it's mostly an accidental working space and I can't help feeling there are others that are better shaped. I have used Bruce Lindblooms BestRGB http://brucelindbloom.com/ when doing scans and it might fit the bill. I know CIE has an RGB space and there's a space called (I think) LStarRGB. I don't know enough about the ramifications of any of these spaces to evaluate their superiority to AdobeRGB.

BTW, when I am shooting for clients and the images color fits within ColorMatchRGB, and I'm supplying RGB files, I use that. Sometimes just sending clients images in a wider gamut space even when the captures are well contained can cause problems if they muck with the files- too easy to make something that looks good on screen and can't be printed. I think this is less of a problem now that more retouchers and printers are getting used to RGB.

What do people think would be the chosen working space for 8 bit if we could all start over without the existence of any current working spaces? ProRGB seems fine for 16 bits. It has almost all the lab colors- of course, it also has a big area outside even LAB.

Ric Cohn
____________________________________________________________________________

Subj: [colortheory] Photoshop LAB Color Book
Date: Saturday, September 10, 2005 6:33:02 PM
From: Lou Dina

Dan,

Your new book is quite wonderful!  I have been Photoshopping for 10 years, but this book has opened up new horizons and explained many things I never understood well before.  Some of it hasn't sunk in very well yet and needs further review, but my images have improved dramatically by applying some of your principles.  Thanks for the fine effort and for pushing the boundaries.  

The hardest part is knowing when to apply which tool and how.  I know it will become clearer with additional experimentation.  This book is well worth every penny and probably one of the best books I have read on the subject.

Well done.

Lou
____________________________________________________________________________

Subj: Re: [colortheory] Photoshop LAB Color Book
Date: Saturday, September 10, 2005 10:46:46 PM
From: Peter Figen

I have to second Lou's opinion about your new book. I've read probably the first six or seven chapters and skimmed the rest, and there have already been many "aha" moments, especially using impossible colors to your advantage. It's a book that I know will take a dozen or more readings to really grasp, but it's the most exciting imaging book I've ever seen. As always, the way the information has been presented never talks down to the reader and is quite humorous. I would expect you to get some criticism from certain corners, but because what you have compiled is so different than any other book I've seen, it's bound to ruffle the feather of some who think they have discovered the only way to do something. It's like how cross country skiing can make a better downhiller, or mountain biking making a better roadie. This book makes me smile to myself when I read it. Thank you.

Peter Figen
____________________________________________________________________________


   Date: Sun, 11 Sep 2005 11:54:45 +0100
   From: Richard Kenward
Subject: Re: Photoshop LAB Color Book

In his posting of Sat, 10 Sep 2005, Peter Figen writes

I have to second Lou's opinion about your new book. I've read probably
the first six or seven chapters and skimmed the rest, and there have
already been many "aha" moments, especially using impossible colors to
your advantage.

Dear Peter

I'm so frustrated, having ordered Dan's book through Amazon on August 17th. and still waiting to receive it. Another computer book ordered at the same time got here within one week so perhaps all UK orders for Dan's book been put on delayed delivery.   I wonder if anyone in the UK has been luckier?

Cheers

Richard
--
Richard Kenward  www.precision-drum-scanning.co.uk (and other services)
____________________________________________________________________________

   Date: Sun, 11 Sep 2005 15:51:48 +0100
   From: "Bob Armstrong"
Subject: Re: Photoshop LAB Color Book

Hi Richard, I'm in Buckinghamshire, UK.

I ordered Dan's book from Amazon UK on 22 August and it was delivered on 7 September.  Isn't it frustrating - and typically the case - that something you're keen to get your hands on is late.  Hopefully, your copy will arrive soon; IMO the wait is worth it.

Regards

Bob Armstrong
____________________________________________________________________________

   Date: Sun, 11 Sep 2005 11:09:22 EDT
   From: Dan Margulis
Subject: Dan's request for images

Folks,

I've been monitoring the list from Photoshop World and would like to thank all who offered suggestions about the next edition of Professional Photoshop and comments about the Canyon Conundrum. I will respond as soon as time permits. Meanwhile, I want to get my request for photographic support out so that I can find out what's available in time to be taken into account as I write.

This follows a very successful use of reader- and student- supplied images in the Canyon Conundrum. Previous editions of Professional Photoshop featured a lot of stock photos that were scanned from film. Today, I think it's more meaningful to have digital captures that are more reflective of what professionals and serious amateurs now confront. I have more than enough pictures to work with now but am willing to spend some time examining more.

I have less of an idea of the type of images that are needed than I did with Canyon Conundrum. There are two items that may require someone to do some extra shooting, and there are three specific areas in which I don't think I have enough examples at the moment.

This is a volunteer army. The motivation would be to provide a service not just to me but to potential readers of the book. I acknowledge up front any people who provided multiple images whether they were used or not, and any pictures actually used are also credited in the rear of the book. Pictures that are used are also placed on the book's CDs but first they are downsampled to 2 mb uncompressed to deter re-use. (Exception: images that demonstrate sharpening or resolution issues go on the CD at full resolution, cropped to prevent reuse if the cropping is possible.)

To judge by past experiences, the generous members of this list will volunteer more images than I can possibly review. So, I'm asking that those interested in participating please e-mail me OFFLINE to describe what you are proposing to send. Please DO NOT send images to my e-mail address. Just describe what you have; if it sounds interesting I'll either ask you to ship me a CD or send me a low-res sample.

The schedule is: if you get me the information this week, I will review it and get back to everyone by Friday 23 September. If I ask you to send the files, I would like to receive them during the week of September 26.

EXCEPTION: note the two "Special Assignments". I am in no hurry for these. They will go in the last chapters that I write. The book has to be divisible by 16 pages exactly. Resolution-related matters are saved until the end because the possible comparisons are unlimited, so they can fill any arbitrary number of pages. If anyone is interested in doing this, please let me know now, but realistically the work wouldn't have to be done until December.

If you are willing to participate, I'm happy to consider anything you consider suitable for the book, but please note my "Special Needs" section below. Just drop me an e-mail describing what you have, keeping the following in mind:

*The book is aimed at professionals or serious amateurs. Therefore, the images should be such that a professional might be called on to correct. Poor originals are more than welcome *provided* that you can explain how a professional might find himself in the position of having to fix it, for example the composition is perfect and can't be duplicated; or this is the actual picture that my client gave me and told me it has to be corrected; or this was a news or sports event that cannot be reenacted; or this picture is of sentimental value to me and I really want to have a good rendition of it; etc.

*The more options, the merrier. In the LAB book, the pictures that I specifically asked for often turned out *not* to be the ones that I actually used, because the photographers generally sent images that they thought were extras but in fact were more instructive for my purposes. So, by all means, if I ask you to send a CD, load it up.

*The images should be UNCORRECTED.

*In your initial message please specify what make of camera was used (if you know), and whether you would be supplying Camera Raw files or some format openable directly in Photoshop. I cannot use images that require proprietary software to open.

SPECIAL ASSIGNMENTS.
1. In the days of drum scanning it was demonstrated that scanning with an excessive resolution harmed quality. I suspect, but don't know for sure, that something of the sort may also be in play with digital cameras. IOW, suppose you have to shoot a certain small product for advertising use. The conventional wisdom is to shoot a closeup, even if this produces a file with much more resolution than  is needed for the advertisement. The question is whether it might produce better quality to shoot a larger scene and crop out what is not needed, thus producing a shot of the product with a lower effective resolution. This can only be tested in the studio because obviously we need carefully controlled conditions to be sure that both the larger and smaller captures are as good as possible before we compare them. Therefore, I would ask for volunteer(s) to shoot several non-moving items at various different effective resolutions. I hope we might be able to get at least two volunteers with two different makes of camera.

2. It would be nice to have a rational discussion of how much quality there is to be gained by shooting in a raw format as opposed to just having the camera generate a JPEG. Acquire modules other than Camera Raw are beyond the scope of the book. Therefore, I would be looking for a variety of shots with a variety of cameras, where there are certain images in a format readable by Camera Raw, and other very similar images shot with the same settings but saved on the camera card as a JPEG. The reason we need several different cameras is that I have reason to think that certain models of camera save really lame JPEGs.

SPECIAL NEEDS.
1. I am short of fashion or glamour photography using PROFESSIONAL MODELS.

2. Scientific, forensic, or military photography, where the typical request is to show as much detail/color differentiation as possible and great color fidelity is secondary.

3. Images that have a story behind them. If we have to fix an inferior image readers get more involved if they understand why a better original could not have been produced and why we should even bother to fix what we have. (For example, the horrifically dark picture of the man receiving an award in Professional Photoshop; this has been one of the most popular examples in the book. Fixing it as an intellectual exercise would not have been as riveting if it had not been explained that the picture was of historic importance, absolutely had to be prepared for publication no matter how bad it was, and that no alternative image existed.)

Thanks in advance to those who are willing to help out--not just from me, but (to judge by the reaction to the LAB book) from your colleagues who will learn from them.

Dan Margulis
____________________________________________________________________________

   Date: Sun, 11 Sep 2005 14:35:42 -0400
   From: Iliah Borg
Subject: digital woes

Dear All,

This is a short list of problems I struggle with editing
digital captures:

- white balance, including mixed light problems
- poor contrast and microcontrast (local contrast) (lack of
pop) (haze)
- poor colour
- false colour in certain colours
- false colour in highlights
- underexposure (to preserve highlights)
- blown-out highlights
- blown-out colour channels
- plugged shadows
- chroma noise in shadows
- luminosity noise in shadows
- overall noise
- moire
- superimposing several exposures to have more dynamic
range
- fringing
- blooming
- chromatic aberration (including increased CA at corners)
- softness of corners
- digital vignetting
- demosaicing artifacts
- JPEG artifacts
- not enough DR (which IMHO is a general term for some problems listed above)
- unadequate colour mapping

I published it on one of the forums in the hope to havecomments/additions/corrections.

Best regards,
ib
____________________________________________________________________________

   Date: Sun, 11 Sep 2005 14:07:16 -0700
   From: "Paul D. DeRocco"
Subject: RE: digital woes

From: Iliah Borg

This is a short list of problems I struggle with editing
digital captures:

With all those problems, maybe you should take up painting. ;-)

However, you neglected to say whether you're using a scanner or digicam, and what model. Many of the problems you describe only occur with some lower quality hardware, and some only occur in certain kinds of images.

I'll comment on a few of the issues.

- poor contrast and microcontrast (local contrast) (lack of pop) (haze)

A useful technique in Photoshop is to use Unsharp Mask with a large diameter, as a way to enhance local contrast without boosting global contrast. It takes some practice to get this right, but it can work wonders. I find that I often start with Levels, adjusted to leave a little headroom, so that the local contrast boost doesn't blow the highlights. Then, I go into Unsharp Mask, set the diameter to something like 100, and play with the amount until I like the results. Then, I tweak the diameter--you generally need a larger diameter if you have an area of clear sky, or can tolerate a smaller diameter if there is detail everywhere. Following that, I sometimes use the history brush to paint back certain specific details that are lost in the highlights or shadows. (You could do the last part with layers and masks, too.)

- moire
- demosaicing artifacts

This is bad hardware design. I use Canon cameras, which tend to have more low-pass filtering in front of their sensors than some other manufacturers, which results in somewhat softer images, but as a result I never ever get this kind of artifact in my images.

- JPEG artifacts

I only use moderately compressed JPEG for the web, where you have no choice. Locally, I save finished edits in JPEG with level 12 compression, and in my rigorous testing I've never been able to see any artifacts.

- chromatic aberration (including increased CA at corners)

Has nothing to do with digital, except that in the digitial domain you can do a reasonably good job of reducing this. The raw converter in PS CS does this quite well.

Ciao,               Paul D. DeRocco
____________________________________________________________________________

   Date: Sun, 11 Sep 2005 23:13:17 EDT
   From: Dan Margulis
Subject: Re: Photoshop LAB Color Book

Richard Kenward writes,

I'm so frustrated, having ordered Dan's book through Amazon on August
17th. and still waiting to receive it. Another computer book ordered at
the same time got here within one week so perhaps all UK orders for
Dan's book been put on delayed delivery.   I wonder if anyone in the UK
has been luckier?

This isn't limited to the UK--they're just having trouble maintaining stock. Amazon likes to keep only a two-week supply on hand, but they had no history on this title--it sold much faster than anybody could imagine. Each one of their orders has been sold out long before they received it. They've been posting a 14-day delivery now for nearly two weeks and *still* the book is in the top four sellers in the computer field, which is AFAIK unheard of for a book that is not available for immediate shipment.

I believe that at this moment there may be no more copies anywhere. I have heard that it's back on press tomorrow, so hopefully everything will go into the pipeline again by the weekend.

Shows like Photoshop World feature large bookstores, but not that many people actually buy there. They're great because they let us page through all the major titles and see what we really want. But lugging a bunch of books around a show floor is a PITA. Every publisher I've dealt with estimates that for each actual copy sold on the floor, 5-10 are sold online. If even 1% of a show's attendees actually purchase a given book on-site, this is considered a significant success.

At PSW, Peachpit brought enough copies for a full 5% of the attendees. They sold out.

Hopefully, your copy is on the way, and not waiting to be received from the printer. There should be ample supply shortly.

Dan Margulis
____________________________________________________________________________

   Date: Sun, 11 Sep 2005 23:19:06 -0500
   From: "Maris V. Lidaka Sr."
Subject: Re: Photoshop LAB Color Book

Amazon.com USA seems fine - I received my copy Friday, within a week of ordering it (using their free shipping, which is supposed to be slower than if I pay for shipping).  Amazon's site generally has a notice on the listing if it's out of stock, or if there are only a few copies left - no such notice at this moment.

Maris
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 08:00:31 EDT
   From: Dan Margulis
Subject: Re: Dan's request for images

Iliah writes,

Do you want some RAW images? And if so, will ACR be the
processor?

I want interesting uncorrected images from a variety of different digicams. If the files are Camera Raw-compatible, fine, but not if they require the vendor's own module. The book is limited to features that exist within Photoshop proper.

Again, anyone who responds to this, please do so off-line.

Dan Margulis
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 08:23:46 EDT
   From: Dan Margulis
Subject: Re: Photoshop LAB Color Book

Maris writes,

Amazon's site generally has a notice on the listing
if it's out of stock, or if there are only a few copies left - no such
notice at this moment.

Look again. On every other title in the top 25, the phrase "Usually ships in 24 hours" appears. On Canyon Conundrum, it reads "Usually ships in 12 to 14 days" . This means amazon.com does not possess copies at present and is waiting on a shipment from the publisher.

"Out of stock" means that the *publisher* has no stock remaining, and has not decided whether to reprint the book. "Out of print" means that no further new copies will be available.

Dan Margulis
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 07:13:43 -0600
   From: Andrew Rodney
Subject: Re: digital woes

On 9/11/05 12:35 PM, "Iliah Borg"  wrote:

- white balance, including mixed light problems
- poor contrast and microcontrast (local contrast) (lack of
pop) (haze)
- poor colour
- false colour in certain colours
- false colour in highlights
- chroma noise in shadows
- luminosity noise in shadows
- overall noise
- superimposing several exposures to have more dynamic
range
- fringing
- blooming
- demosaicing artifacts
- JPEG artifacts
- not enough DR (which IMHO is a general term for some
problems listed above)
- unadequate colour mapping

Shoot RAW and then nail the converter and conversions. While you can't fix every issue above, you can greatly reduce them.

- underexposure (to preserve highlights)
- blown-out highlights
- blown-out colour channels
- plugged shadows

Shoot Raw correctly (Expose to the right). Blown out highlights are fixed by exposure IF the highlights really are all blown out which you can only see in a good RAW converter (and in the case of ACR, recover to some degree). If you can't light the entire scene to match the dynamic range, you'll have to sacrifice shadows but with a good sensor and RAW handling (or HDR), you can get a great deal of data in either end of the tone scale.

Using Smart Objects is a great way to mate up multiple RAW conversions to extend the range.

Andrew Rodney
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 09:54:10 -0400
   From: Iliah Borg
Subject: Re: digital woes

Dear Andrew and Paul,

Thank you for the responses. I will try to explain what I meant.

Not only I shoot RAW, but I shoot exclusively RAW (uncompressed if it is Nikon).

I'm processing raw images captured by other photographers as well, hundreds of them, as I need that to understand features we need to include in our own converter.

The "digital woes" list was mainly for Dan to see what (if any) he can cover in his 5th edition. I distributed the list among my friends ("advanced amateurs" and "pros") and none of the items was considered "minor" in their feedback.

For each of the items in the list I can suggest real-world (no pun) examples, some of them are photographer's errors, some are inevitable because of shooting conditions.

Many of the items are just results of poor RAW conversion - some are postprocessing errors, and some are due to limitations of hardware, and some are due to processing algorithms used in raw converters. Here you can see demosaicing artifacts example: http: //rawmagick.us/compareall2.htm
Those who use ACR IMHO need to know how to get rid of that maze patterns.

As far as I understand, the book will not deal with educating readers on shooting, though some mentioning of photographical errors would be most welcomed by majority of readers. So, we have a captured original we need to improve - and we are dealing with combination of user errors (photo and PP), hardware and software limitations. Hence the list.

For the record, images I'm talking about are captured with dSLRs, mostly top of the line Canon and Nikon equipment.

Best regards,
ib
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 10:36:01 -0400
   From: Lee Clawson
Subject: Re: digital woes

on 9/11/05 2:35 PM, Iliah Borg wrote:
 
This is a short list of problems I struggle with editing
digital captures:

Iliah,

Your list might just cover all the photo problems. I sure hope this is not the norm for you.

Lee
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 10:04:51 -0500
   From: "Maris V. Lidaka Sr."
Subject: Re: Photoshop LAB Color Book

Right you are!  That means I got one of their last remaining copies :-)

Maris

Dan Margulis wrote:

Look again. On every other title in the top 25, the phrase "Usually
ships in 24 hours" appears. On Canyon Conundrum, it reads "Usually
ships in 12 to 14 days". This means amazon.com does not possess
copies at present and is waiting on a shipment from the publisher.
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 11:42:30 -0400
   From: Iliah Borg
Subject: Re: digital woes

Dear Lee,

My "statistics" shows that about 30% of images I deal with exhibit 1 or more of the woes I listed. Maybe my view is distorted, same as the view of a surgeon in an emergency ambulance :).

Best regards,
ib
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 12:30:20 -0400
   From: Lee Clawson
Subject: Re: digital woes

And 70% are fine...I don't think that's too far from a average statistic. If you want suggestions to better these "statistics" I'd go with refining exposure especially during the capture then looking at the RAW conversions (sort of what Andrew is talking about). White balance (a pet peeve of mine) would be next.

Lee
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 09:33:43 -0600
   From: Andrew Rodney
Subject: Re: Converting from Lab into CMYK and RGB

On 9/12/05 8:31 AM, "Ric Cohn"  wrote:

Andrew- I honestly don't understand your point. Are you saying the
profile preview is perfect and if a printer doesn't match it it's
because their press conditions don't match TR001? I thought TR001 was
suppose to be both an aim point and a reflection of achievable results
from average well-profiled SWOP presses?

I'm saying the U.S. Web Coated (SWOP) v2 profile was built based on actual spectral measurements that conform to a true specified standard of SWOP called TR001.

This process produced a very specific recipe for SWOP based on measured empirical data that thankfully anyone with the hardware and interest can produce and verify. Therefore, TR001 measurement data describes expected SWOP behavior for printing presses, proofing systems, and separations.

This assumes the correct viewing conditions and you should keep in mind the white of the paper.

That said, if you want to talk profile preview in terms of soft proofing, there's a slew of other factors, the display and profile of the display just one.

Did you look at the particular conversion preview I'm talking about?

There's little need. I have no idea how the press dealt with the numbers it was provided. If we know that the press sheet conformed to TR001 and the matching profile was used, at this point we'd have something to start looking into. At this point, do we know the press did conform to TR001?

Photoshop has no less than 2 SWOP settings right out of the box and they are not the same. I know one conforms to something that is defined with concrete data. The other, who really knows.

Andrew Rodney
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 12:57:46 EDT
   From: Dan Margulis
Subject: Re: Converting from Lab into CMYK and RGB

Ron Kelly writes, with respect to my statement in the LAB book that I chose sRGB and SWOP v.2 as default spaces solely because they are "consensus" and not because I endorse them,

Okay, you've made that point several times in the Lab Book and  
elsewhere. What settings do you recommend when you aren't so  
constrained?

As this topic takes an entire chapter in Professional Photoshop, it is not amenable to a brief answer.

With respect to RGB, at present around 95% of users employ either sRGB or Adobe RGB. There are several threads on the pluses and minuses of each in our list archives. I have a worksheet/checklist that I would use to decide which is appropriate, in

http: //www.ledet.com/margulis/ACT_postings/ProfilingandProofing/ACT-sRGBvAdobe_2004.htm

Dan Margulis
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 12:13:49 -0600
   From: Chris Murphy
Subject: Re: Eighteen Questions about Dan's new LAB book

On Sep 3, 2005, at 9:40 PM, Andrew Rodney wrote:

In LAB (well CIEXYZ of which
LAB is based) as well as the spaces you mention above, the colors are not
imaginary but they can certainly be outside of the gamut of a lot of
devices.

CIE LAB and CIE XYZ by definition do not contain imaginary colors, only real ones that the standard observer can see. But encoded LAB does contain a rather large percentage of imaginary "colors." Encoded LAB is a cube, but CIE LAB isn't. CIE LAB doesn't have a color 0L*,-128a*,128b*, and yet you can define such a thing in encoded LAB.

So if the LAB value being used is outside of the CIE LAB gamut, if you will, then it's an imaginary color.

Chris Murphy
Color Remedies (TM)
www.colorremedies.com/realworldcolor
____________________________________________________________________________


   Date: Mon, 12 Sep 2005 10:04:47 -0700
   From: "Paul D. DeRocco"
Subject: RE: digital woes

From: Iliah Borg

Many of the items are just results of poor RAW conversion -
some are postprocessing errors, and some are due to
limitations of hardware, and some are due to processing
algorithms used in raw converters. Here you can see
demosaicing artifacts example:
http://rawmagick.us/compareall2.htm
Those who use ACR IMHO need to know how to get rid of that
maze patterns.

You can't. Once aliasing has occurred, it can't be mathematically distinguished from real detail. It can only be suppressed with an antialiasing filter in front of the sensor.

Ciao,               Paul D. DeRocco
____________________________________________________________________________

   Date: Mon, 12 Sep 2005 16:20:33 -0400
   From: Iliah Borg
Subject: Re: digital woes

On Mon, 12 Sep 2005 10:04:47 -0700 "Paul D. DeRocco"  wrote:

You can't. Once aliasing has occurred, it can't be
mathematically distinguished from real detail.

that is not aliasing that occured during digital capture. Those in the example above are demosaicing artifacts. That is why different programs using different demosaicing algorithms produce them to different amounts :) But if that pattern occurs, some kind of actions similar to moire supression is in order. I can also suggest examples when moire itself is caused ny improper demosaicing rather then aliasing :)

Best regards,
ib

____________________________________________________________________________


   Date: Fri, 16 Sep 2005 03:09:06 -0000
   From: "davidmadison"
Subject: Re: You're Number One

Dan, in my opinion the success of your book is because enough of the market is ready for HIGH LEVEL Photoshop books.  Many of us don't need to read more of "Scott's Ht 100 Top Photoshop Tips".  Your book is one of the very few high level books ever published on PS.  Keep them coming!

David Madison
____________________________________________________________________________

   Date: Fri, 16 Sep 2005 10:25:52 -0000
   From: "franklin2812001"
Subject: Canyon Stuff

Well, I received my copy of Dan's book yesterday from amazon.de and immediately went to work. Two curiosities-on page 8 Dan writes that the files on the CD are RGB originals and that we should duplicate and shift to LAB mode. In fact the files are in LAB mode, as is stated in the word info page provided on the CD. Am I missing something here? Well I did open figure 1.2 and this figure seems to be fully corrected; at least on my screen (Eizo Flexscan T965, calibrated weekly with i1 and Profilemaker Pro 5.0). Curious, n'est pas? I should add that figures 1.8 and 1.10 are not corrected. Anyhow I did follow the recipes for 1.8 and 1.10 and then tried a few of my own files with mindblowing results. I am sure you will hear more from me soon.

Richard M. Franklin
____________________________________________________________________________

   Date: Fri, 16 Sep 2005 09:26:18 EDT
   From: Dan Margulis
Subject: Dan's response re Professional Photoshop

This is a response to the many comments and suggestions about planning the 2006 edition of Professional Photoshop. They have changed my mind about two areas. I was surprised by how many people wanted a strong channel-blending section. I will upgrade what I had been planning.

Also, at first I did not think that Iliah's list of common problems was particularly useful. Outside of issues of noise and moire reduction, everything is covered within the "color by the numbers" philosophy, so that anyone who truly understands the first half of the book would automatically have solved these problems. I now think, however, that it would be better to reinforce that at the end of the book. There is already a section in the final chapter that discusses how you would know when looking at a picture whether you wanted to correct it in RGB, LAB, or CMYK.  I think there ought also to be a reverse list, that is, if you have Problem A in the image, it indicates that Procedure B should have been used.

RESPONSE TO THE LAB BOOK
I agree with those who said that we need to know why Canyon Conundrum is doing so much better than anyone predicted before doing anything irreversible with Professional Photoshop. At the time I posted the inquiry, we were guessing, but now it's pretty clear what has happened and why I didn't foresee it.

In my classes, I give a 2-3 hour introduction to LAB before anybody starts working in it. Students therefore have seen some of the fanciest stuff before they try the simple things. I have not had experience with people who have just been introduced to the most rudimentary LAB move (i.e. Chapter 1) and are struggling with it without knowing exactly where the book is going to go with it.

That basic symmetrical move in the A and B curves, however, seems enormously powerful to people who are trying it out for the first time. Readers seem to have been able to figure out what type of image it works on best, and they are getting immediate results from it. I had thought that the book would appeal largely to an intermediate-advanced audience because most of the later chapters contain information that is available nowhere else. Everybody who's gotten to the second half of the book likes that, too, but the big push is from people who have gotten through only a chapter or two and found that it completely changed their workflow. These are the people who are doing the big word of mouth. It's only now that people are coming forward to say that they are getting a lot out of the later chapters. I still have hardly seen any commentary past Chapter 11.

For the channel-blending part of Professional Photoshop, we may be able to shoot for the same thing: an immediate boost in quality, folllowed by a more detailed explanation.

AREAS OF AGREEMENT
*As to the concern that I might do just a quick update to get the book out the door, no need to worry about it. As some of my recent posts have indicated, at some point in the near future I am going to have to decide what I intend to do when I grow up. I've already said that 2006 will probably be the last year for the Makeready column. One would have to suspect that this will be the last rewrite of Professional Photoshop, although I don't know for sure yet. I have a lot of interest in life outside of color. Certainly I would want this one to last for four years or so, just as the current edition has. I have no intention of having what is potentially my last book be an inaequate one.

*The comment by Dick Lutz about scientific imaging is well taken. I did put out a request for such images but to date have no good ones.

*We definitely need a section on where Camera Raw fits into a sensible workflow. However, we will not go into specific shooting techniques. We have to assume that the start point is a photograph that has already been taken, and that the end point is a print-ready file.

AREAS OF DISAGREEMENT
*There will be no change in title. First-time authors get pushed around considerably by their publisher. In 1994, I wanted to call the book "Professional Color with Photoshop", and I wanted a larger trim size. I lost these battles, in the first case because the publisher wanted to trick general Photoshop users into buying it, and in the second because it would have been more expensive to print.  For this forthcoming edition, I plan to go to the 8x10 size of Canyon Conundrum, which will enable larger images. However, there is just too much equity in the Professional Photoshop name, which I still don't like, to consider changing it. Googling it gets tens of thousands of hits.

*I am not going to change my basic writing style in favor of a step-by-step approach. These books are intended to teach people to *think* about color and not just to spit out a recipe. As for the jokes and literary allusions, they're staying in, too. The subject is difficult, and whatever can be done to make the book more appealing bedtime reading is IMHO appropriate.

*Professional photographers are *part* of the target audience for this book, not the be-all and end-all. Many "amateur" photographers are at least as good, and more motivated to improve, than many "professionals." Plus, there's a whole universe of people who don't claim or aspire to be good photographers at all, but whose job is image prep. In my view, anybody who potentially could justify spending 15 minutes on an image could also potentially be a reader.

*The book needs to retain its focus. Workflow-related topics that are specificto individual users are secondary. We will not discuss specific brands of printer or camera unless there is some highly unusual characteristic.

*While I agree that the treatment of sharpening needs to be expanded, and that there the topic is very deep, I disagree that a book about sharpening only would be economically viable and I have no intent of producing one.

*It was pointed out that at least two new books are in the works on channel structure. If it turns out that neither one is what people are looking for, and if there is no new edition of Photoshop Channel Chops, then we can revisit the question of a book on channel blending.

*************************

About twenty people have replied to my request for images for this book, which is more than enough. I will be responding to them in the next couple of days, as well as posting a second request for specific types of images at a later time.

I would like to thank those who took the time to post to the thread, and also for those who have offered constructive feedback about the Canyon Conundrum.

Dan Margulis
____________________________________________________________________________

   Date: Fri, 16 Sep 2005 11:19:00 -0400
   From: John Ruttenberg
Subject: Dan's response re Professional Photoshop

I wasn't able to follow all the suggestions about the next edition of this book, but I do have a request.  I'd like to have in-depth coverage of shadow/highlight.  What does it do, exactly?  What's the best way to approach it?  Is it equivalent to some sort of curves, blending, &etc move?
____________________________________________________________________________

   Date: Fri, 16 Sep 2005 10:19:03 -0500
   From: "drhobbes"
Subject: Re: Dan's response re Professional Photoshop

In my own experience, the most valuable thing in Professional Photoshop, outside of your treatment of Curves, has been your discussion of channel blending, channel mask-making, and use of the Channel manipulation tools Apply Image and Calculations.  Most of the images with which I work are watercolor paintings with very subtle shifts of tone, pastel colors in some areas, metallic elements, strong contrasts and sometimes little contrast of any kind.  Usng channels in working on these images has sometimes proved to be more valuable than working with Curves.  Some images have even been corrected using various forms of channel manipulation instead of Curves.  In case you wonder if this is due to lack of knowledge of and experience with LAB, RGB, and CMYK, it is not.  Following your repeated advice, I always go with the color mode that works best for the job at hand, sometimes making use of all three when the need arises.

While your Canyon Conundrum is on my must-own list, I'm still preoccupied with finding new ways to apply the information in Professional Phtoshop 7. Your consideration in supplying a CD for this book has made it extremely valuable for experimentation.

As for giving up writing Photoshop articles and books, Dan, please reconsider.  There must be thousands more like me who never would have made signficant progress in mastering such a difficult subject without your guidance.  If you do change your mind, please consider a book on the subject of commercial printing.  You must be one of the very few individuals who understand the entire process from scanning to final printing.  Judging from the posts in the ColorTheory forum, there are tens of thousands more who badly need this kind of knowledge.

Howard Smith
____________________________________________________________________________

   Date: Fri, 16 Sep 2005 12:06:02 -0700
   From: Jono Moore
Subject: Re: Dan's response re Professional Photoshop

On 9/16/05, John Ruttenberg wrote:

I wasn't able to follow all the suggestions about the next edition of this
book, but I do have a request.  I'd like to have in-depth coverage of
shadow/highlight.  What does it do, exactly?  What's the best way to approach
it?  Is it equivalent to some sort of curves, blending, &etc move?

Excellent tutorial here, in the meantime:
http://www.naturescapes.net/062004/gd0604.htm

____________________________________________________________________________

   Date: Sat, 17 Sep 2005 09:11:11 -0700
   From: Melvin Strawn
Subject: Re: Dan's response re Professional Photoshop

Dan,

A question for you re the audience for Prof Photoshop (& Canyon Conundrum, which I am working through): Many of us are not Photographers as such, but use PS - and your books, among others- to develop our images and prepare them for print, usually on our own  or a service bureau's digital printers, EPSON, HP, Falcon, etc.. Some of our images use scanned or photographed inputs. We use layers a lot - and, at least in my case, get flattened images that look decidedly different than the all-layers-open composite view - which one expects to see when
flattened.

You talk about only wanting photographs to work with for the new book. Are you interested in some other, "fine art" digital collage, mixed input type images? (See the examples in Going Digital - well, they all did start with photos..). Or, as I suspect, you may consider that an image is an image and no special problems attend non photographic or mixed input images?

Thanks for your book(s), columns and consideration of this.

Mel
____________________________________________________________________________

   Date: Mon, 19 Sep 2005 01:53:09 EDT
   From: Dan Margulis
Subject: Re: Canyon Stuff

Richard Franklin writes,

Well, I received my copy of Dan's book yesterday from amazon.de and
immediately went to work. Two curiosities-on page 8 Dan writes that
the files on the CD are RGB originals and that we should duplicate and
shift to LAB mode. In fact the iles are in LAB mode, as is stated in
the word info page provided on the CD. Am I missing something here?

I never said that the files on the CD are RGB. I offered a general recipe for a user who was unfamiliar with LAB. The first step for such a user is to convert the file into LAB. Plainly, if the file already is in LAB (as the files on the CD are) there is no need for this first step.

Well I did open figure 1.2 and this figure seems to be fully
corrected; at least on my screen (Eizo Flexscan T965, calibrated
weekly with i1 and Profilemaker Pro 5.0). Curious, n'est pas? I should
add that figures 1.8 and 1.10 are not corrected.

This appears to be author error. This image on the CD is neither the original nor the corrected version, but rather a version to which the wrong RGB profile was assigned when converting. While I will correct this for the next printing, it should have almost no effect on the way one would apply curves to the A and B channels and very little on the L (the image on the CD is darker, not more colorful, than the actual image identified as the original in the book.)

Dan Margulis
____________________________________________________________________________

   Date: Mon, 19 Sep 2005 09:07:35 EDT
   From: Dan Margulis
Subject: Re: Dan's response re Professional Photoshop

Mel writes,

Dan,
Many of us are not Photographers as such, but use PS - and your books, among
others- to develop our images and prepare them for print, usually on our own  
or a service bureau's digital printers, EPSON, HP, Falcon, etc.. Some of our
images use scanned or photographed inputs. We use layers a lot - and, at least
in my case, get flattened images that look decidedly different than the
all-layers-open composite view - which one expects to see when flattened.

I don't know of any situations where the Layer: Flatten Image command would cause a change in the appearance of the file. If the image is being flattened during a conversion to another colorspace, then yes, appearance can change.

You talk about only wanting photographs to work with for the new book. Are
you interested in some other, "fine art" digital collage, mixed input type
images? (See the examples in Going Digital - well, they all did start with
photos..).

While these are certainly interesting exercises they would expand the scope of the book, when the biggest problem is to keep it down to a manageable size while covering color correction of photographs comprehensively.

Or, as I suspect, you may consider that an image is an image and no special
problems attend non photographic or mixed input images

You suspect incorrectly. There are several differences, and I've written about them on several occasions, but I don't propose to cover them to any length in Professional Photoshop.

Dan Margulis
____________________________________________________________________________

   Date: Mon, 19 Sep 2005 21:24:28 -0000
   From: Stephen Marsh
Subject: Re: Dan's response re Professional Photoshop

--- DMargulis  wrote:

I don't know of any situations where the Layer: Flatten Image command would
cause a change in the appearance of the file. If the image is being flattened
during a conversion to another colorspace, then yes, appearance can
change.

Agreed Dan, Adobe put in an alert box about this.

Mel, this happens when you are not viewing at 1:1 or 100% view, due to view magnification interpolation errors I presume. Next time it happens, undo the conversion, view at 100% and then reflatten, the appearance should not change.

As I hav mentioned in the past, 25% view seems more reliable than 50% - but 1:1 view is ideal for a 'true look' (not what I would have thought).

Stephen Marsh
____________________________________________________________________________

   Date: Sat, 24 Sep 2005 10:49:41 -0000
   From: Stephen Marsh
Subject: Re: You're Number One

Dan, you and your publisher probably are thinking on this point, but if not...

Your new LAB book has been selling far better than expected. There have been many positive reader reviews and it would seem that some readers are amazed at the results that they are seeing.

How many of these readers are new to your books? Perhaps expect Professional Photoshop to pickup in sales, as more new readers look for other books from you, after they have absorbed some of the LAB stuff.
 
I think it is important for you and your publishers to understand which segments of the market are finding this truly amazing, is it coming from those who listen to conventional wisdom and thus shun LAB due to the touted negative issues that it has and may have never seen such techniques as you introduce in PP or in Canyon? Is it coming from readers of your past work, who have a much higher level of expectation than somebody who has not seen less conventional ways of editing an image (what, no selection?).

Stephen Marsh.
____________________________________________________________________________

   Date: Sat, 24 Sep 2005 20:26:52 EDT
   From: Dan Margulis
Subject: Re: Re: You're Number One

Stephen Marsh writes,

Your new LAB book has been selling far better than expected. There
have been many positive reader reviews and it would seem that some
readers are amazed at the results that they are seeing.
How many of these readers are new to your books?

Of the ones who are in fact amazed, probably most of them. They're the ones with no LAB experience at all.

Perhaps expect
Professional Photoshop to pickup in sales, as more new readers look
for other books from you, after they have absorbed some of the LAB stuff.

That could be, but I don't think right away--the LAB book is a considerable handful. I do suspect, though, that the current edition of Professional Photoshop will sell out before the next one is ready.

I think it is important for you and your publishers to understand
which segments of the market are finding this truly amazing, is it
coming from those who listen to conventional wisdom and thus shun LAB
due to the touted negative issues that it has and may have never seen
such techniques as you introduce in PP or in Canyon?

They seem to be largely professional or serious amateur photographers. They pick up some of their own pictures, not mine, and give the first LAB recipes a try. Then, they're amazed for two reasons: they've previously worked on the image for 45 minutes and thought they had something good; and they try on a new copy of the original with LAB for 30 seconds and get something that's obviously much better. People who aren't willing to work for 45 minutes on a picture aren't so amazed, because they have nothing to compare it to.

The question was whether these people were going to be able to differentiate an image that was good for LAB from one that wasn't. That was why I started with a chapter entirely on canyons, hoping to bash the concept into the readers' heads, at the risk of having people think that working on nothing but canyons was a big bore. Apparently the readers have been able to work it all out, because the images they're showing are good choices.

Is it coming from
readers of your past work, who have a much higher level of expectation
than somebody who has not seen less conventional ways of editing an
image (what, no selection?).

We are talking about, in effect, two sub-books here. The first, much smaller book, is the one that causes amazement. The larger one is the one that appeals to serious retouchers and to those who have had some LAB experience. There was the possibility that one of the sub-books would be favorably received and the other not. Fortunately, both groups are giving it a big thumbs-up, and members of both groups are saying that their workflows are going to change. That's what's driving the unexpectedly high sales, IMHO. It's one thing to have a bunch of people who obviously haven't had much experience with LAB being really happy, but the recommendation is much reinforced when you hear it from people who clearly know what LAB is all about and why it's important.

Dan Margulis