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
___________________________________________________________________________
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
___________________________________________________________________________
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
___________________________________________________________________________
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 http://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
___________________________________________________________________________
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
___________________________________________________________________________
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
___________________________________________________________________________
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
____________________________________________________________________________
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.  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.  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.  Does Adobe Capture RAW
run on LAB?
No.
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?
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.  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.  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."Â Â Your
bias here is not my experience.Â
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.  On page 106:Â
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.  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.  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.  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.  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.  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.  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.  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.  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.  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.  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
