Adobe Photoshop Training with Dan Margulis

Dan Margulis Applied Color Theory

Is the Raw Format Better than JPEG?

Date: Sat, 20 Sep 2003 16:00:36 -0600

From: Ron Kelly

Subject: jpeg vs. RAW for camera capture

Dear Group:

I've been using a digital camera for about 6 months now, and I just love it. It's been a big productivity boost for me.

I know there are lots of knowlegeable opinions on this list who might enjoy sharing their opinions on a couple of questions about what is the best way to write data from such devices at the time of capture.

1. Does RAW capture allow for lossles color correction, by means of changing the color temperature setting, for example, through post-capture processing? Or is this just another way of applying a curve or level change to the data, and therefore not lossless? How could it be otherwise?

2. How does exposure compensation on RAW images work through software? Is it as good as capturing the best exposure at the time? How could it be?

3. Jpegs are a way of compressing data before writing it, and so information is lost and unwanted artifacts created. Are there any more disadvantages to jpeg as compared to RAW if one is skilled in the ways of images curving a la Photshop?

My guess based on conversations I've had is that people tend to go all one way or the other on this question, and they just use all RAW or all jpeg. Is there any one out there who uses both? If so, why, and when?

Thanks in advance,

Ron Kelly

____________________________________________________________________________

Date: Sat, 20 Sep 2003 15:55:19 -0700

From: David Cardinal

Subject: RE: jpeg vs. RAW for camera capture

1. Does RAW capture allow for lossles color correction, by

means of changing the color temperature setting, for example,

through post-capture processing? Or is this just another way

of applying a curve or level change to the data, and

therefore not lossless? How could it be otherwise?

Raw allows the white balance correction to be done after the fact rather than at the time of shooting. Either way the white balance correction is _mostly_ a multiplication of red & blue by a ratio depending on color temperature (and then optionally some fancy matrix math to adjust for illuminant type). It is lossless (except if it causes you to blow out highlights) whether done in camera (JPEG) or in the computer (Raw). However, Raw lets you change it later and have it still be lossless, while the Gamma (Tone) encoding used for JPEG means that if you change WB later on the computer there is some loss.

2. How does exposure compensation on RAW images work through

software? Is it as good as capturing the best exposure at the time? How

could it be?

Somewhat similarly, since the Raw image is not yet Gamma (Tone) encoded, you have the full 12-bit linear data to use on the computer. You can shift the exposure up and down and _then_ do your encoding into 8-bits. It doesn't increase the total dynamic range, but it does allow you to decide after the fact where you want your exposure to fit within the range the camera captured initially.

3. Jpegs are a way of compressing data before writing it, and

so information is lost and unwanted artifacts created. Are

there any more disadvantages to jpeg as compared to RAW if

one is skilled in the ways of images curving a la Photshop?

If you can keep your WB within around 1000 degrees and your exposure within a stop, and don't need to do other massive PS corrections, then JPEG corrections work quite well.

That said, I'm sure plenty of folks will insist they just plain get better results with Raw, so at some point it becomes a religious issue.

I have an article in the September Outdoor Photographer that goes into more detail on these tradeoffs, and illustrates them with some images.

My guess based on conversations I've had is that people tend

to go all one way or the other on this question, and they

just use all RAW or all jpeg. Is there any one out there who

uses both? If so, why, and when?

I use both. JPEG when I'm confident and need the speed, Raw when I'm not at all sure about the correct WB or exposure and don't have time to figure it out, or when I want to use the image in several different ways that will require drastic WB shifts.

Hope that helps, but there are many different opinions on this topic, so please experiment and see what works for you!

--David Cardinal

http://www.nikondigital.org

____________________________________________________________________________

Date: Sun, 21 Sep 2003 05:27:22 -0500

From: Bob Smith

Subject: Re: jpeg vs. RAW for camera capture

On Saturday, September 20, 2003, at 05:55 PM, David Cardinal wrote:

If you can keep your WB within around 1000 degrees and your exposure

within a stop, and don't need to do other massive PS corrections, then JPEG

corrections work quite well.

David gave an excellent description of the differences. I'll add my two cents.

If you're going to process out the raw files to exactly the same settings (WB, exposure comp, color space, sharpening etc) as the camera will use to create jpegs, then there is little if any difference in the image. I know many who shoot jpegs this way and are perfectly happy with the results. You're essentially working like you would shooting transparency film... nail the exposure and color balance at the time of capture and you're good to go. The downside is that you're missing out on the versatility and margin for error that a raw file affords. Shooting raw is like shooting neg film. Expose now, figure out how to interpret to a final image later. With a difficult subject I'll often process the raw file several different ways and blend the images with layer masks in Photoshop. That makes easy work of mixed lighting situations; or subjects with an extremely broad range of brightness.

Part of the choice of raw or jpeg depends on the particular camera as well. Kodak cameras for example are built around a raw file work flow and they do that very well. The cameras slow to a crawl when shooting jpegs. The only reason to shoot jpegs with these cameras is to save space on the camera card. Nikon is almost the opposite. They're blazingly fast shooting jpegs and you give up performance to shoot raw. It just depends on the basic design philosophy of the camera's hardware/firmware. Also the quality and efficiency of raw file processing software varies greatly between cameras as well. If the raw processing software for your camera is a pain to use you might be more inclined to live with the limitations of jpeg.

Bob Smith

____________________________________________________________________________

Date: Sun, 21 Sep 2003 14:45:23 EDT

From: Joe Butts

Subject: Re: jpeg vs. RAW for camera capture

In a message dated 9/21/03 1:59:26 AM Mountain Daylight Time, colortheory@yahoogroups.com writes:

<<Is there any one out there who uses both? If so, why, and when?>>

Yes, Ron, I use both jpeg & RAW formats. I use RAW when, like David said, I am not sure about getting the color balance and/or the exposure close enough. In addition, I use RAW if I know I'm going to be going to larger prints (20x30 & larger) or of groups of people where the head sizes are smaller.

My experience a couple years ago after some rather extensive testing was that jpeg will create a slight color artifacting compared to the RAW. This artifacting was most evident when white and a darker or warmer color (skin tones) were adjacent to one another. Now, on a head and shoulders portrait (I photograph people mostly), this was not really evident until we got into larger sizes (like a 20x30) and then I had to really sniff the prints. But, on a full length family group and going to just 16x20, the eyes and teeth took on the flesh color. Now, that looked really BAD! I've learned how to correct it quickly and easily in Photoshop with a brush in color mode, but why should we have to do that? That takes time and does effect the final image in some adverse ways. You know, change the pixels and degrad the image. If only I could capture everything just the way I want the final image to look, then my prints would exceed the quality I was getting from my film and Hasselblads.

I hope this helps you some.

Joe Butts

<A HREF="www.joebutts.com">Joe Butts Photography</A>

505-388-2826

____________________________________________________________________________

Date: Tue, 23 Sep 2003 15:21:14 +0100

From: "Michael Wilkinson

Subject: Re: jpeg vs. RAW for camera capture

I never shoot JPEG ,only raw as you never know when you may need the raw quality file.

Its rather like saying shall I use 5x4 or 35mm.I realise that we all have our own

requirements but for me Raw is the only option.

Michael Wlkinson

____________________________________________________________________________

Date: Tue, 23 Sep 2003 11:42:17 EDT

From: Paul Harding

Subject: Re: jpeg vs. RAW for camera capture

Come on guys and gals .. HOW MANY viewers can tell the diff between a RAW file and a JPEG? I still contend that the message is more important than the messanger .. look at all the crap that passes out they for "corrected" images.

Regards

Paul Harding

JIT Graphics

____________________________________________________________________________

Date: Tue, 23 Sep 2003 13:11:15 EDT

From: Dan Margulis

Subject: Re: jpeg vs. RAW for camera capture

Paul Harding writes,

Come on guys and gals .. HOW MANY viewers can tell the diff between a RAW file and a JPEG?

100 percent of them, because the raw file hasn't been corrected yet whereas the JPEG ordinarily has had some kind of balancing routine and/or range extension applied to it.

I suspect you are suggesting that a *corrected* raw file can't be told apart from a similarly corrected JPEG without closer inspection tools than are usually available to the nonprofessional viewer. In principle, that's true, but there's a big gotcha.

By-the-numbers color correction works by in effect changing the conditions under which the camera saw the image. If the camera sees a cast, for example, we consider this to be incorrect, but at least the camera is incorrect in a consistent way that we can attack with curves.

Correction becomes much more difficult if somebody else has horsed around with the digital file first. That's the problem with the standard JPEGs: the software has already extended range and balanced the endpoints which may or may not be the right thing to do with a given image. So the colors the camera originally saw are corrupted by the time we get to attack them.

The bottom line is that a skilled user will likely get better results from the raw file, not because JPEG has artifacting or not enough bits or whatever the latest theory is, but because the capture is free from undesired intervention, human or otherwise.

Dan Margulis

____________________________________________________________________________

Date: Tue, 23 Sep 2003 17:27:35 -0400

From: Dolores Kaufman

Subject: Re: jpeg vs. RAW for camera capture

Dan Margulis wrote:

Correction becomes much more difficult if somebody else has horsed around

with the digital file first. That's the problem with the standard JPEGs: the

software has already extended range and balanced the endpoints which may or may

not be the right thing to do with a given image. So the colors the camera

originally saw are corrupted by the time we get to attack them.

I can vouch for that! I just spent the afternoon color correcting a dozen images sent to me over the internet in JPEG format. The image quality wasn't a problem as the images will be printed very small (less than 1.5 in. sq.) and most only needed a curve to lighten and some minor color tweaking, but 3 of them were a nightmare. They were portraits (done in a studio) and the skin tones were lacking any C whatsoever and the values were between 10 and 15%. Somebody (or something) had obviously had a go at these. I finally managed a passable result but it wasn't a whole lot of fun!

Dolores

____________________________________________________________________________

Date: Wed, 24 Sep 2003 19:09:05 -0400

From: "Jerry L. P'Simer"

Subject: Re: jpeg vs. RAW for camera capture and new Question

Dan Margulis wrote:

The bottom line is that a skilled user will likely get better results from

the raw file, not because JPEG has artifacting or not enough bits or whatever

the latest theory is, but because the capture is free from undesired

intervention, human or otherwise.

Hello Everyone

It's been awhile since I have posted here. I mostly lurk.

I agree totally with Dan's statements above, I purchased a digital camera last November for personal use (Canon G2). I used the jpg format for the first few months that I had the camera and it worked quite well but had some difficulties with several pictures that I shot due to strange lighting conditions and other things as well. I started shooting everything in the camera's raw format and then downloading them to my computer and convert them without any of the camera's settings applied. Ever since I have done this I am able to achieve better results than I had previously been able to. It is more work and I can't put as many images on my cards, but the results are superior and worth the extra time spent.

This brings me to a new question. I often assign false profiles to bring the raw data into an acceptable range for further correcting and then convert to my working space. (colormatch rgb) I have several that I created and use frequently. I am trying to help a friend of mine to do this as well but the problem is... he uses a PC and I use a Mac. I do not know how to save the profiles to the correct location on his PC so that they are available for use inside of photoshop by using the assign profile command. On my mac I can access these profiles in the same location as the default RGB profiles that ship with PS and it is very simple to use them. I have had no luck doing this on a PC. Can anyone tell me how to do this so they will be convenient to use on a PC as well? This probably sounds like a dumb question to many but I just don't use PC's and have no clue how to go about this the correct way.

Thanks in advance.

Jerry P'Simer

____________________________________________________________________________

Date: Wed, 24 Sep 2003 23:33:38 -0500

From: David Riecks

Subject: Re: jpeg vs. RAW for camera capture and new Question

At 07:09 PM 9/24/2003 -0400, Jerry L. P'Simer wrote:

This brings me to a new question. I often assign false profiles to bring

the raw data into an acceptable range for further correcting and then convert

to my working space. (colormatch rgb) I have several that I created and

use frequently. I am trying to help a friend of mine to do this as well but the

problem is... he uses a PC and I use a Mac. I do not know how to save the

profiles to the correct location on his PC so that they are available for use

inside of photoshop by using the assign profile command.

Jerry:

Is he using Windows 98, Win2K or WinXP. I don't believe the place is the same for all. The "Real World Color Mgt" book, co-authored by Chris Murphy (probably heard of his name, eh?) covers this pretty thoroughly.

With WindowsXP, and photoshop 7, this should do the trick:

C:\Program Files\Common Files\Adobe\Color\Profiles\Recommended

If not that, then

C:\Program Files\Common Files\Adobe\Color\Profiles\

Also, don't forget that the windows system will need to see the ".icc" or ".icm" windows "extension" on the file in order to recognize it for what it is.

Hope that helps.

David Riecks (that's "i" before "e", but the "e" is silent)

http://www.riecks.com , Chicago Midwest ASMP member

____________________________________________________________________________

Date: Thu, 25 Sep 2003 06:32:28 +0100

From: "Michael Wilkinson"

Subject: Re: jpeg vs. RAW for camera capture

Come on guys and gals .. HOW MANY viewers can tell the diff between a RAW

file and a JPEG? I still contend that the message is more important than the

messanger .. look at all the crap that passes out they for "corrected" images.

Paul Harding

There is a Big difference between a Jpeg and a RAW file properly processed and saved to TIFF.

I accept that we all have our own requirements for final output but for me its rather like opting for 35mm rather than 5x4".

The bigger format gives more flexibility and "Future proofs" your filed image.

And Yes,I can tell the difference.

Regards

Michael Wilkinson. 106 Holyhead Rd, Ketley, Telford, Shropshire. England .TF1 5DJ

44 (0) 1952 618986. www.infocus-photography.co.uk

For Negatives & transparencies from digital files

____________________________________________________________________________

Date: Thu, 25 Sep 2003 09:26:19 +0100

From: "Bob Frost"

Subject: Re: jpeg vs. RAW for camera capture and new Question

Jerry,

It depends on which Windows OS he is using. On XP the default folder is Windows/System32/Spool/drivers/color. Some programs set up other directories for their own profiles, but this is the system folder for profiles.

Bob Frost.

____________________________________________________________________________

Date: Wed, 24 Sep 2003 20:23:22 -0500

From: "Maris V. Lidaka Sr."

Subject: Re: jpeg vs. RAW for camera capture and new Question

What OS for the PC? Under Windows 98SE the profiles go into to the directory "Windows\Systems\Color"

Maris

____________________________________________________________________________

Date: Thu, 25 Sep 2003 08:30:12 -0700

From: "Raymond E. McKinley"

Subject: Jpeg vs RAW

The profiles are saved in the following locations in these versions of Windows

Windows 98- The Windows\system\color folder

Windows 2000 - The WinNT\system 32\spool\drivers\color folder

Windows XP - The Windows\system 32\spool\drivers\color folder.

Raymond

____________________________________________________________________________

Date: Thu, 25 Sep 2003 09:32:00 -0300

From: "Ellie Kennard"

Subject: Re: jpeg vs. RAW for camera capture and new Question

If he is on XP, and the file has either a .icc or .icm extension on it, he just has to right click, and will have the option 'install profile' then it puts it in the right place without all that drilling down.

HTH

Ellie Kennard

Innovative Imaging Studio

http://www.iiStudio.com

____________________________________________________________________________

Date: Thu, 25 Sep 2003 09:49:29 EDT

From: Paul Harding

Subject: Re: jpeg vs. RAW for camera capture

In a message dated 9/25/03 8:14:13 AM, Michael Wilkinson writes:

And Yes,I can tell the difference.

My original reference to the RAW and JPEG files was for the large population of "viewers" ( read customers ) who probably can't even spell JPEG or RAW. They ONLY want their "stuff" done on time and ready for distribution. The message gets lost in all of the "color" correction .. as an airbrush/technical illustrator for over 30 years, I struggled for a time trying to reconcile droplets of paint/ink to pixels on screen. We in the business have trained our eyes to "see" the slight color casts and imperfections in our work. I don't suggest that all images are acceptable as taken or painted or drawn or scanned.

I called a wide format printer the other day and he had no clue as to what a "profile" was let alone "embedded" .. he just takes the client files to RIP and prints.

Regards,

Paul Harding

JIT Graphics

____________________________________________________________________________

Date: Thu, 25 Sep 2003 09:32:57 -0500

From: John Opitz

Subject: RE: Installing ICC profiles in Windows Platform

Jerry P'Simer wrote:

I can access these profiles in the same location as the default RGB

profiles that ship with PS and it is very simple to use them. I have had no luck doing

this on a PC. Can anyone tell me how to do this so they will be convenient

to use on a PC as well?

Install those false profiles in the following locations:

Windows 2000: WinNT/System/Spool/ Drivers/Color.

Windows NT: WinNT/System32/Color.

Windows 98: Windows/System/Color

John Opitz

p.s. It's nice to know how to use both platforms. Just like how to use

RGB,CMYK and LAB.

____________________________________________________________________________

Date: Thu, 25 Sep 2003 09:30:43 -0700

From: "Michael Stokes"

Subject: RE: RE: Installing ICC profiles in Windows Platform

Or Right-click on the profile and select "install profile"

Michael Stokes, Microsoft Corporation

P.S. WinNT has no platform color management support, it is strictly

application color management support.

____________________________________________________________________________

Date: Thu, 25 Sep 2003 16:58:32 -0400

From: "Jerry L. P'Simer"

Subject: Re: jpeg vs. RAW for camera capture and new Question

David Riecks wrote:

Is he using Windows 98, Win2K or WinXP. I don't believe the place is the

same for all. The "Real World Color Mgt" book, co-authored by Chris Murphy

(probably heard of his name, eh?) covers this pretty thoroughly.

Thank you all who responded to my question. I do have "Real World Color Mgt" and it did not even occur to me to look for the answer there. I think that I can handle it now. I'm still not sure of the OS that my friend is using but I will find out this weekend. With all of the responses that I was given I'm sure that one of them will work for me.

Cheers

Jerry

____________________________________________________________________________

Date: Thu, 25 Sep 2003 16:13:32 -0400

From: "Pylant, Brian"

Subject: RE: jpeg vs. RAW for camera capture and new Question

I agree totally with Dan's statements above, I purchased a

digital camera last November for personal use (Canon G2).

I also use a Canon G2 as my main digital camera (great unit, can't speak highly enough about it) and I too have found that for critical work RAW is the way to go. For casual photography I certainly use JPEG (and not even the highest resolution; I need to maximize my CF space when I'm on vacation, for example, so I use the SuperFine setting at the second-highest resolution, which creates JPEGs at approximately 1MB per image) but for my serious work I wouldn't consider using any of the JPEG modes.

I'm sure this carries over to other makes and models as well.

Brian

Adobe Photoshop training classes are taught in the US by Sterling Ledet & Associates, Inc.