sRGB vs. AdobeRGB

What are the real differences between sRGB and AdobeRGB?
I have heard conflicting responses.
I shoot Raw on 7D with Mac Aperture. Thanks.

I would like to know this too!

The difference between sRGB and AdobeRGB is that the latter has a wider gamut = range of colours.

Have a look at the stickies in this section "RAW, post processing and printing" where Rene Damkott posted an excellent explanation about "color space" and color management" with links to more about this subject.

Anyone who asks "which color space should I use" should use sRgb, as should anyone who doesn't understand the difference. The reason is sRgb is more compatible and easier to get right.

I am taking a Photoshop class and our instructor had us convert to AdobeRGB.
I never used it before.
Just learning about it.
I understand the color gamut. Just wondering if I then have to convert all pictures to be sent over the internet,website etc. to sRaw.
Tim do use Adobe or sRaw?
Thanks.

What I use is irrelevant, I have a fairly comprehensive understanding of color, it's digital representation, how color profiles work, etc. I also have multiple output media, which require a variety of color spaces.

sRaw is a file format, which has no color profile. You mean sRgb, Adobe RGB has theoretical advantages for some images, though your media has to support it - ie your print lab. For the web all images should be sRgb.

I've written all this before, so has Rene, we've gone over and over what people should use and why. Rene has a sticky thread about color. I suggest you read all that, and then realise when we say "use sRgb unless you know exactly what you're doing" we mean it. sRgb is pretty much indistinguishable from any other color space 99% of the time, for 99% of people.

If you are going to put your images out to the public, whether on the Web or email, delivering them on a CD, you have to assume that their image viewers won't display Adobe RGB properly and you will be sad. So, yes, if you are working with Adobe RGB, convert your "output" images to sRGB. Then you'll be happy.

A lot of mainstream commercial printers will only accept sRGB images too.

I've stuck with sRGB as I don't "need" Adobe RGB; if I get anything commercially printed it has to be sRGB and if I post anything to the web it should be in sRGB to allow for those with non-colour managed browsers.

Adobe RGB may be beneficial if you're printing a lot at home I guess or if you're a pro whose client specifically requests it.

Note: Many inexperienced people mistakenly say. "AdobeRGB has more colors." This is absolutely wrong. The number of possible colors is determined by the bit depth. Every jpg is always 8 bits per channel, 24 bits total, 16 million possible colors. AdobeRGB covers a wider range of colors, but that also means that in order to cover the wider range with the same number of steps the gaps between colors are wider.

tim wrote in post #9341682
What I use is irrelevant, I have a fairly comprehensive understanding of color, it's digital representation, how color profiles work, etc. I also have multiple output media, which require a variety of color spaces.

sRaw is a file format, which has no color profile. You mean sRgb, Adobe RGB has theoretical advantages for some images, though your media has to support it - ie your print lab. For the web all images should be sRgb.

I've written all this before, so has Rene, we've gone over and over what people should use and why. Rene has a sticky thread about color. I suggest you read all that, and then realise when we say "use sRgb unless you know exactly what you're doing" we mean it. sRgb is pretty much indistinguishable from any other color space 99% of the time, for 99% of people.

Sorry Tim. sRGB not sRaw. That's what happens when you stay up late.
Brain needs sleep.

tzalman wrote in post #9342302
Note: Many inexperienced people mistakenly say. "AdobeRGB has more colors." This is absolutely wrong. The number of possible colors is determined by the bit depth. Every jpg is always 8 bits per channel, 24 bits total, 16 million possible colors. AdobeRGB covers a wider range of colors, but that also means that in order to cover the wider range with the same number of steps the gaps between colors are wider.

Please describe what's in "the gaps between the colors."

Also please tell me how your rules work with 48 bit color or, for that matter, with 96 bit color. Are the gaps even bigger?

Hen3ry,

Instead of "gaps", think of the gamut stretching or shrinking to fit into whatever space is available, is that a better analogy?

Oversimplified, but does this diagram help?

Edited to add: There are loads of sRGB v aRGB comparisons on the internet. I typed into my search engine aRGB and got almost 8000 results.

I print at home with a printer that can use aRGB so thats what I use. If you farm your printing out, or don't print at all, or post most of your work online, then I'd suggest sRGB.

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Lowner wrote in post #9343765
Hen3ry,

Instead of "gaps", think of the gamut stretching or shrinking to fit into whatever space is available, is that a better analogy?

No, not really

I think I understand the gaps to be a single point of color representing a group of adjacent colors in the visible spectrum that can't be represented in a hardware system because of the limitations of the hardware and the abstraction of the arithmetic used to describe it.

Does that make sense?

Lowner wrote in post #9343765
I print at home with a printer that can use aRGB so thats what I use. If you farm your printing out, or don't print at all, or post most of your work online, then I'd suggest sRGB.

I use Adobe RGB on my R2400, Mac Pro and W7 systems, and I agree completely about SRGB.

Hen3Ry wrote in post #9343665
Please describe what's in "the gaps between the colors."

Also please tell me how your rules work with 48 bit color or, for that matter, with 96 bit color. Are the gaps even bigger?

Imagine you are in a big room and you have 256 cards that you have to lay on the floor, equally spaced, from one side of the room to the other. After you have arranged the cards there are three inches from each card to the next one in line. Now you take your cards next-door to a larger room and lay them down. Because the room is larger the cards are now five inches apart. Those cards represent colors. The rooms are color spaces. When the transition from one color to another is very small the human eye can't see that they are separate discrete colors, we see a smooth gradient. This is one of the things that makes a photo look so much more life-like than even the most realistic painting. But when the change from one color to the next is bigger the gradient is no longer smooth. We start seeing that they are discrete colors and we have what is known as "banding"

As we edit an image the tones tend to get spread out and become fewer. A 8 bit image has 256 tones (16 million colors). This is more than the eye can see - around 200 tones (11 million colors). This is a pretty large margin of safety, but if we try to push the editing too far the number can come down so low that we start seeing banding This is particularly true in the dark parts of an image where we start off with fewer tones. Because AdobeRGB starts off with bigger spaces between the colors, compared to sRGB, the limit is reached faster. If we were to use a really huge space like ProPhotoRGB in 8 bit, it would be just about impossible to do any editing without causing banding. But with 16 bit this is not a problem. With 65,536 levels per channel (4 trillion colors) the gaps are so tiny that even after extensive editing when we go down to 8 bits for output there are no visible gaps.

For this reason we say that a RAW shooter should do as much editing as he can in the RAW converter, where the bit depth is 14 bits, before exiting with a jpg.

Nick5 wrote in post #9341583
I am taking a Photoshop class and our instructor had us convert to AdobeRGB.

Did they explain why? If they didn't, and they didn't explain the various pitfalls then they're not much of an instructor.