Adobe RGB vs sRGB vs ProPhoto RGB
Mac versus PC, RAW versus JPEG, Coke versus Pepsi, all solid battles in their own right but Adobe RGB versus sRGB is still one that confuses more people than anything else. One of the problems is that there is big name experts on both sides of this argument arguring why their side is right and the other is totally off-base. What we will try to do is to show how both affect images so that you can choose the right one for your situation.
What exactly is this colorspace stuff anyway? Basically its the amount of color that is contained in the file when you save it. The three most common colorspaces are Adobe RGB, sRGB, and ProPhoto RGB. As my friend Rick Miller puts it, you can relate gamut to containers of beer. With sRGB being a 12oz can of beer, Adobe RGB would be a pony keg, and ProPhoto RGB being a full kegger.
The image shown here (courtesy of Cpesacreta) shows the relative sizes of the different colorspaces.
The difficulty here is knowing when to use which colorspace. Who would take a 12 ouncer when they can have a whole keg right? You would think, but the problem is that not all devices can actually display the larger colorspace which can cause even more problems when it comes to viewing the images, add to that the lack of color management in most applications (like web browsers) and you will often get dull or washed out colors when viewing the images.
Wait a second, huh? If you use a colorspace that allows MORE colors, than why would the images look WORSE when viewing them? The answer that since almost no devices can actually display Adobe RGB, you wind up with an intepretation of the image causing it to look dull.
Effects of Color Space
Does all of this really make a difference? Let’s take a look at some images that were shot in RAW (thus no colorspace recorded on capture) and then saved as both Adobe RGB and sRGB using Adobe Photoshop Lightroom.
Adobe RGB
sRGB
Adobe RGB
sRGB
In all of these cases, the images saved as sRGB should appear more vibrant in Internet Explorer and Firefox since they are not color managed applications. Apple’s Safari browser is supposed to properly display Adobe RGB files and Firefox is supposed to have color management in upcoming versions. However, until everyone is using a browser you should avoid Adobe RGB in order to provide the best images to the widest audience.
What about ProPhoto?
ProPhoto offers the widest gamut of the available common color spaces so should have a place somewhere right? Well yes it does. The best use of the ProPhoto is to use it within your workflow to preserve the largest amount of color in your images and then only do a final conversion to sRGB when saving your images as jpegs. This is quite easy with Photoshop and Camera Raw while Lightroom uses ProPhoto RGB internally (Geek Note: Actually, Lightroom uses Melissa RGB which uses ProPhoto RGB chromatisity values working in linear gamma, named after Melissa Gaul, one of the Lightroom engineers).
Should you shoot in Adobe RGB or sRGB?
This is another tough question that different people will answer differently. The simple answer is niether. Shoot in RAW and convert to the colorspace you want during your workflow process. If you want to shoot in JPEG then you have to make the choice. The best thing to do is actually experiment with your equipment and software to determine what gives you the best results. Some people think you should shoot in Adobe RGB and then convert to sRGB if the file is for the internet, while others think you should shoot in sRGB so no conversion or translation is applied, thus you should get more accurate color representation.
In the end, you have to make up you own mind as to what works best for you, but you do need to be aware of the differences and some of the issues you can run into based on your choice.
Author: Kerry Garrison
References used in this article
http://www.cambridgeincolour.com/tutorials/sRGB-AdobeRGB1998.htm
http://www.kenrockwell.com/tech/adobe-rgb.htm
http://www.steves-digicams.com/techcorner/October_2006.html
http://www.smugmug.com/help/srgb-versus-adobe-rgb-1998
great article. the one thing that you did not discuss is for prints. it sounds like to me that Adobe RGB or ProPhoto would be better for prints to get the most color range, but is this true? this topic applied to prints is really what confuses me.
This is going to depend on your lab and what they use. I work at one of the top labs in the country, and we print everything in sRGB, because our lab networking setup (Kodak DP2) can't process Adobe RGB or ProPhoto RGB in a way that translates well to paper. The images simply look too flat. So we convert all images that aren't already sRGB to that so they will print with the best reproduction we can offer.
Hope it's ok for everyone if I add a comment to this "not new, but still relevant" thread.:
If you print at home on a high level ink printer, then it might be also a considerable option to use Adobe RGB since those printers are capable to print color saturation values beyond sRGB in the color space of Adobe RGB. But check your printer manual. In any case, if these differences in color matter to you, it would be necessary to calibrate your monitor screen and your printer (based on the paper you are going to print on) to be able to see the color improvements using Adobe RGB on your print. Otherwise you end up with more dull colors on paper than if you would have stayed with sRGB right from the beginning all the way through.
Tks for this article, now this thing of color space is more clear to me.
You want use whatever your printer uses, usually Adobe RGB, but check with your printer settings.
Hey Kerry, interesting post here. Not sure I understand the color space to shoot in being answered with “shoot in raw” because I always thought RAW didn't really deal with color spaces. On my 40D I am shooting in raw but still am able to shoot in either Adobe RGB or sRGB.
Also, a great reference on the ProPhoto color space with really good graphics to illustrate the differences can be found at: http://www.luminous-landscape.com/tutorials/pro…
The in-camera settings for colorspace are only applied if you are shooting in JPEG. If you are shooting in RAW then it is not converted into a particular color space until you bring it into an editor. With Camera Raw the option is at the bottom of the screen.
Really? I did not know that – see ya learn something new every day, thanks Kerry!
I shoot in RAW and my camera is set to sRGB (which I know doesn't mater in RAW) and I have the Color Space in CS4 set to sRGB. Why does CS4 tell me that the profiles do not match? I bring the files off of the camera onto the Mac via Bridge. Is there something in bridge embedding Adobe RGB?
Thank you! In the last couple of months I had been fighting with color shift issues between PS and web. I think you just provided my answer!!
I have not seen this happen myself. Could be that the embedded jpeg preview image is storing the profile, but it shouldnt that I know of.
was having trouble with this the othe rday. I shoot adobe rgb and sometimes forget to convert srgb.. results not soo cool when that happens.. Srgb if its gonna go on the web for certain. but if i'm printing adobe rgb.. based on what ya'll are saying I should probably give prophoto A try for my next prints.
Firefox has had color management capability since v3. The only sticky point is that it is turned off by default. You can follow these instructions to turn it on:
http://www.robgalbraith.com/bins/content_page.a…
check your workflow settings in Adobe Camera Raw (clickable blue line at bottom of ACR window). It's probably set to Adobe RGB.
It's like a funnel. If you start at the big end you have lots of choices and you can choose. If you start at the small end (sRGB) you are stuck with your intial choice and cannot make changes later.
Don;t start at the small end if you care about quality.
go here for a complete explanation:
http://www.gballard.net/psd/go_live_page_profil…
Good article, but one question I have yet to see an answer to is whether there is a quality difference between editing in a large gamat like ProPhoto and then converting to sRGB as a last step vs just using sRGB all the way through the workflow.
Also, most monitors can't even display aRGB let alone ProPhoto, so when editing you don't even see some colours while editing. Larger gamats are great in theory, but until we have screens and graphics cards that can display them the advantages will remain nothing more then theory.
Good points but it kind of like saying we dont need 24 megapixels over 16 megapixels or 14 bit over 8bit. If you are starting in a smaller gamut then you will start clipping color data right from the beginning. If you start with a larger color gamut you have more data to work with to come up with your final image. You dont want any clipping to occur until your last step in the process for best results.
Will you be able to tell a difference in most cases? Probably not, but as system improve, monitors improve, and output devices improve, yes you will.
Rez is rez, although it may not matter when outputting to the web or printing small, rez does help when printing really big and there is a somewhat of a quality boost by capturing 24mp the down sizing to 12 vs just capturing 12.
I can actually see the difference when editing a 16 bit file vs a 8 bit file. You can start to see banding if you push those pixels to far.
But I have never seen the difference between editing in a large gamat then rendering down to a smaller gamat vs just working with the smaller through out the workflow. Whether the colours are clipped before or after editing, they are gone are they not?
I agree that you want to capture the most amount of data for future use, I always suggest shooting RAW, but when you end result is going to be sRGB anyways…..
Yes you will lose data but you have more control over the data you lose. You can see this in Photoshop by changing the display gamut. You dont have any control over the preview in Lightroom yet though.
I think I understand, so it's like blown highlights, if you shoot JPEG those highlights are gone, if you blow then while shooting all that detail is gone. But if you shoot RAW, you can recover some of the detail in those highlight before converting to Jpeg.
By editing in a larger gamat, you can recover some of those colours that would normally be tossed when you render down to a smaller space, did I get that right?
I guess that is where LR really shines, you can tame the colours in there before outputting a file in a smaller space for final touches.
One question, do you know what space the histogram in Lightroom represents? It would be nice to know what is going to be clipped before exporting
Thats the best way of looking at it. Granted its pretty deep technically and I am trying to understand it the best I can based on what my pals at Adobe are telling me. But yes, thinking of it like highlights being blown is a great analogy.
A good article with good comparisons. I am enjoying your blog- Nate
Thanks for this article. What I get from this is that images for web display only should be converted to sRGB, and images that will be used for prints should be in ProPhotoRGB or Adobe RGB? Is that right?
Excellent article, thank you for the infos down here.
In terms of effects, srgb is better.
so in photoshop how do you convert to sRGB??? form RGB
The easy way is when you use the “Save for web” click on the “convert to sRGB” checkbox.
I've had some trouble getting my mind around this concept of colour spaces. But I'm beginning to think it's a lot like a 24 bit version of the old 8 bit indexed colour format. So we seem to have returned to that old piece of technology.
At the same time I'm thinking that widening the colour space must make the distances between shades greater. The classic sRGB model is like a cube with even sides, R, G and B standing for X, Y and Z respectively. In that space the distance between (192, 192, 192) and (192, 192, 193) is 0.8. But if you stretch the outer limits of the box, the inner distances must stretch too, because we are still operating in 8 bits per channel. So the previously mentioned distance can grow to 2 or even 4. That must mean that we lose subtle shades that we had in the sRGB model, mustn't it?
I've had some trouble getting my mind around this concept of colour spaces. But I'm beginning to think it's a lot like a 24 bit version of the old 8 bit indexed colour format. So we seem to have returned to that old piece of technology.
At the same time I'm thinking that widening the colour space must make the distances between shades greater. The classic sRGB model is like a cube with even sides, R, G and B standing for X, Y and Z respectively. In that space the distance between (192, 192, 192) and (192, 192, 193) is 0.8. But if you stretch the outer limits of the box, the inner distances must stretch too, because we are still operating in 8 bits per channel. So the previously mentioned distance can grow to 2 or even 4. That must mean that we lose subtle shades that we had in the sRGB model, mustn't it?