sRGB versus RGB

mercphoto

I'm confused about color spaces. I know RGB is "bigger" than sRGB. I also know that sRGB is roughly the gamut of a monitor, which is slightly bigger than that of printers. Simplification, I know, but its close enough for discussion.

Should I upload Adobe RGB, or should I upload sRGB jpg's to smugmug? Seeing as how I'm a person who does little post-processing, should I just shoot my 20D on sRGB JPG and be done with it?

Thanks.

DavidTO

And another thing...

What's with sRGB and sRGB IEC61966-2.1?

Really confusing, and a pain in the butt.

dkapp

mercphoto wrote:

I'm confused about color spaces. I know RGB is "bigger" than sRGB. I also know that sRGB is roughly the gamut of a monitor, which is slightly bigger than that of printers. Simplification, I know, but its close enough for discussion.

Should I upload Adobe RGB, or should I upload sRGB jpg's to smugmug? Seeing as how I'm a person who does little post-processing, should I just shoot my 20D on sRGB JPG and be done with it?

Thanks.

You should upload to smugmug in sRGB. Browsers only show this profile, so pictures in aRGB will appear flat & washed out.

I shot in aRGB & change to sRGB before I upload.

Hope this helps.

Dave

pathfinder

dkapp wrote:

You should upload to smugmug in sRGB. Browsers only show this profile, so pictures in aRGB will appear flat & washed out.

I shot in aRGB & change to sRGB before I upload.

Hope this helps.

Dave

I absolutely agree with dkapp. I save my files in my archives on my hard drive as 16bit *.psd in AdobeRGB. But when I upload a file to smugmug I convert them to 8 bits via Image>Mode>8 bits/channel and then Image>Mode>Convert to Profile and use these settings



If you do not specify sRGB, smugmug strips the ICC info and the image ends up looking kind of less saturated than it should.

Baldy

pathfinder wrote:

If you do not specify sRGB, smugmug strips the ICC info and the image ends up looking kind of less saturated than it should.

Oh boy, this is a big issue. cry:cry It will look washed regardless of whether we strip the ICC profile or not because no Windows browser knows for ICC profiles.

Here's our help topic on it: http://www.smugmug.com/help/display-color

It's not true that Adobe RGB is bigger — it has the same number of bits to represent it — but it is true that it's broader — it can represent more colors, but in coarser gradations since it has the same number of bits to cover a broader area.

It turns out the conversion from Adobe 98 to sRGB is hard because some computer has to make decisions for you about how to represent colors in the Adobe 98 file that don't exist in sRGB.

So.... Counterintuitively, you end up with a poorer sRGB file by going through Adobe 98 first.

In most cases, and to most eyes, it won't make a difference because few naturally occurring colors are outside sRGB, especially ones that can be printed or displayed.

Since virtually all pro and consumer printers in the US expect sRGB files, including EZ Prints, Ofoto, Shutterfly, Costco, Walgreens, Wolfe's, whcc, and the web expects sRGB, our advice is to stick with it unless you have a client who expects Adobe 98 (a magazine, for example).

Thanks,
Baldy

mercphoto

Baldy wrote:

Since virtually all pro and consumer printers in the US expect sRGB files, including EZ Prints, Ofoto, Shutterfly, Costco, Walgreens, Wolfe's, whcc, and the web expects sRGB, our advice is to stick with it unless you have a client who expects Adobe 98 (a magazine, for example).

You just made my life, from here on out, easier. The 20D is being switched to sRGB for most my shooting from here on. Thanks everyone!

marlinspike

Bill, just so you know, even if you set it to sRGB, if you are shooting in RAW it won't make a difference (except maybe with canon's raw conversion software, I'm not sure). With Adobe you have to select sRGB in the raw conversion (same screen where you adjust color temp and exposure and what all). Luckily, once you set it, it always does it.

Richard

DavidTO

DavidTO wrote:

And another thing...

What's with sRGB and sRGB IEC61966-2.1?

Really confusing, and a pain in the butt.

Good info, but still, what about this?

Baldy

sRGB is almost always shorthand for sRGB IEC61966-2.1. Unlike CMYK, which has a bunch of variants, sRGB IEC61966-2.1 is the standard Windows default. Far as I know, the IEC blah blah designation was added to standard RGB (which is what sRGB was named after) when ANSI adopted it as a standard.

Likewise, Adobe 98 is variously referred to as Adobe RGB, aRGB, Adobe RGB (1998) and SMPTE-240M just to confuse everyone as much as possible.

DavidTO

Baldy wrote:

sRGB is almost always shorthand for sRGB IEC61966-2.1. Unlike CMYK, which has a bunch of variants, sRGB IEC61966-2.1 is the standard Windows default. Far as I know, the IEC blah blah designation was added to standard RGB (which is what sRGB was named after) when ANSI adopted it as a standard.

Likewise, Adobe 98 is variously referred to as Adobe RGB, aRGB, Adobe RGB (1998) and SMPTE-240M just to confuse everyone as much as possible.

Well, I set my JPEGS on my NEW 20D to sRGB, and it comes out with all the extra stuff on the end. I also set PS to sRGB, but when I open a file from the camera, I get a mismatch because it says it's a different profile. All this on a Mac.

Baldy

Odd. I have a 20D set to sRGB and a Mac and don't get that. Anyone have an answer?

DoctorIt

DavidTO wrote:

Well, I set my JPEGS on my NEW 20D to sRGB, and it comes out with all the extra stuff on the end. I also set PS to sRGB, but when I open a file from the camera, I get a mismatch because it says it's a different profile. All this on a Mac.

I don't think its a Mac thing, I think its a PS settings issue. What Baldy said about shorthand for the names is one thing, but PS definitely has 2 distinguishable color profils for sRGB and sRGB blah blah blah IEC200393949. So you're getting that mismatch, I'd try the other sRGB setting and that should fix it. I've played with both of those color spaces and I can't see the difference, so maybe it's just stupid name game that PS has to play to keep all cameras happy??


In either case, Baldy, thanks for the great info. I had given up on the "broader" aRGB a long time ago when all my web images looked flat. It always bothered me knowing that I was working in an inferior color space, but now that I know its actually what 99% of the world (browsers, printers) expect, I'm much happier!

Baldy

It takes some conviction to use sRGB when no less an expert than Bruce Fraser is fond of saying, "if your file is destined for print, sRGB is a poor choice."

And Scott Kelby, author of many best-selling Photoshop books and the president of the National Association of Photoshop Professionals, says in one of his books, "The first thing you should do is change Photoshop's default color space to Adobe 98. sRGB is fairly ghastly for photographers. I wouldn't even recommend it to web designers."

I think it kills Bruce that the web doesn't make use of his beloved ICC profiles, but there's no way CNN and eBay are going to triple the size of small images by attaching the profile.

(Ironically, the images Bruce uses on his website to show the gamut of Adobe 98 are actually sRGB files with no ICC profile attached.)

And it kills Scott to think that a camera could capture a color that sRGB can't reproduce perfectly.

But as Dan Margulis is fond of saying, the sRGB tide swept the web and printing services and many color experts are having trouble coming to grips with it. But he also says sRGB covers virtually all naturally occurring colors and it's an unusual image that has something outside sRGB's gamut. And Adobe 98 is the worst of the RGB spaces if your file is bound for CMYK, he says (I don't know why that's true).

Anyway, the web is an sRGB world and we have to deal with it. Going Adobe 98 doesn't improve the situation, it worsens it.

I see absolutely stunning images in sRGB every day.

DoctorIt

Baldy wrote:

And Scott Kelby, author of many best-selling Photoshop books and the president of the National Association of Photoshop Professionals, says in one of his books, "The first thing you should do is change Photoshop's default color space to Adobe 98. sRGB is fairly ghastly for photographers. I wouldn't even recommend it to web designers."

His books are specifically why I felt bad for using sRGB. That jerk!