PetaPixel

Why You Should Probably Use sRGB

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When I first started using Adobe Camera Raw, one of the options I experimented with was which color space the resulting JPEG should be in. Not thinking it mattered, I selected “Adobe RGB (1998)”. However, a few days later I suddenly realized that the images looked different in a browser than when I had saved them in Photoshop. The once rich and vibrant colors were gone, and what I saw were images that were washed out and desaturated. After looking into why this happened, I found out that the problem had to do with color space.

Color Spaces

So what is a color space anyway? Basically, it’s a specific range of colors that can be represented. JPEG images offer the same number colors no matter what color space you use, with the difference being the range of the colors that can be represented. In other words, sRGB can represent the same number of colors as Adobe RGB, but the range of colors that it represents is narrower. Adobe RGB has a wider range of possible colors, but the difference between individual colors is bigger than in sRGB.

To illustrate this, I’ll use a simplified example. Suppose my color space consisted only of blue, and I could have a total of 3 possible colors. Lets say I chose to use the following “color space”:

srgbrange

Now, maybe I would like a wider range of colors to work with for one reason or another. Though I can’t increase the number of colors I can represent, I can increase the range by spreading the colors farther apart. The resulting color space might look something like this:

adobergbrange

Notice how I was able to capture a wider range (or gamut) of possible colors without increasing the number of colors. In both “color spaces”, I’m limited to 3 colors.

In the same way, Adobe RGB captures the same number of colors as sRGB but offers a wider range of colors by spreading the colors out more.

sRGB

sRGB is pretty much the default color space everywhere you look. This means that most browsers, applications, and devices are designed to work with sRGB, and assume that images are in the sRGB color space. In fact, most browser simply ignore the embedded color space information in images and render them as sRGB images.

Pros

  • Displayed consistently across all programs
  • Simplifies workflow
  • Suitable for normal prints
  • Most people can’t tell the difference anyway

Cons

  • Narrower range of colors than Adobe RGB
  • Can’t obtain benefits of Adobe RGB later down the road

Adobe RGB (1998)

As I explained earlier, Adobe RGB represents a wider range of possible colors using the same amount of information as sRGB by making the colors more spaced out. Since sRGB has a narrower range of colors than Adobe RGB, it cannot display certain highly saturated colors that could still be useful in certain applications, such as professional-grade printing. Thus, photographers and graphic artists that need this extra color range for specific purposes would choose Adobe RGB over sRGB.

Pros

  • Wider range of colors than sRGB
  • Better for professional prints
  • Can always obtain benefits of sRGB later down the road

Cons

  • Will be displayed incorrectly by most browsers
  • Complicates workflow

Which to Use

First of all, if you publish your images on the web, you should always save and publish them as sRGB. This is because most browsers will render images as sRGB regardless of what you save it as, causing Adobe RGB images to appear desaturated and washed out (the problem I was experiencing). Thus, if you want your images to look the same regardless of where it’s being displayed, you should always publish them as sRGB. This makes it so what you see when you save is what you get when it’s displayed.

Thus, the question becomes, “what color space should I work with and save images as?”. This is more tricky, and generally depends on your workflow and what you use your images for.

If you work with 16-bit images and need the extra color range (or gamut) for professional-grade printing, then you should save your images in Adobe RGB. This preserves the extra color information that would be lost if you saved as sRGB, just like the extra information in RAW files is lost if you save them as JPEGs. In this case, it’s not the amount of data that’s lost, but the range of colors.

If you might need the wider range offered by Adobe RGB anytime in the future, then you should work with and save your images in Adobe RGB. If you save your images as sRGB, you cannot convert it to Adobe RGB in the future to obtain the wider range of colors.

However, the advantage of working in sRGB is that it simplifies your workflow. You don’t need to worry about color spaces at all if you’re only going to publish your images to your Flickr or personal photoblog. All you need to do is save the sRGB images and upload them to the web, and they will look fine.

Conclusion

Unless you know specifically you want to work in Adobe RGB, make sure all your devices and programs are set to work in sRGB. Otherwise, you might find out one day that your images look horrible on other people’s browsers! I found this out the hard way.


Image credit: Clock Study #4 by David H-W (Extrajection).


 
 
  • http://nyuu.ro/ yoshi

    You could work in AdobeRGB and convert to sRGB just before publishing on net.

  • http://www.joshbobb.com/ Josh Bobb

    I agree. It's nicer to capture/process in AdobeRGB or ProPhotoRGB and then downsample to sRGB. “Save for Web” in Photoshop takes the guesswork out for amateurs.

  • joakimbergquist

    Well said… there is simply no reason to not use sRGB for the mundane photographer.

  • Adam

    You should note that if you shoot in RAW, there is not really a color space assigned to the image; the color space only really comes into play when you save it down to a non-RAW format.

  • http://twitter.com/BretLinford Bret Linford

    A slightly better workflow, IMHO, is to always work in a larger space such as Adobe1998. But, only convert to a smaller color space upon output. Output could be sRGB for web, a custom cmyk printer profile for whatever type of printing you are doing or whatever. This way you are not limited by sRGB's limitations

  • http://twitter.com/darraghs darraghs

    Very good tutorial on colour management
    http://www.cambridgeincolour.com/tutorials/colo

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  • http://nilshot.com/ Zach Stern

    That's awful. You should NEVER shoot in srgb, however you should always convert to sRGB before posting a photo to the web.

  • http://shuttersounds.thedailynathan.com/ Nathan Yan

    AdobeRGB is not all positives. You have to remember we're dealing with digital files with a limited bit depth here: for JPEGs we're dealing with 8 bits, for instance. That gives us 256 possible values. Most cameras these days will produce RAW images with 12 or 14 bits, so that's 4096 or 16,384 possible values, respectively.

    So saying “yes, color is a continuous spectrum so the wider the range we can capture the better” is true IF we were working in the analog domain. However, we're working with digital, which is unable to sample infinite points but will now condense the continuous spectrum into only 16k or 4k or 256 discrete points.

    So while srgb gives us a smaller range to work with, we are able to describe the colors in that range much more precisely, given the limited sample points we have.

    As a simplified example, let's take a description of “blue” that ranges from say 0-100, continuously in real life. Say our sRGB can only cover the 35-65 range for this blue, while Adobe RGB can cover the 20-80 range. Adobe RGB can cover a superset of sRGB's colors, right? Not so in the digital domain.

    Now for simplicity's sake, say we're working with 2-bit images, which gives us 4 possible values. With sRGB then, we could describe the points 35, 45, 55, 65. With Adobe RGB, the colors we could describe would be 20, 40, 60, 80.

    Now imagine how the colors from subjects in the scene would map to digital values in either of these schemes. What if we had say a blue flower petal, whose tones ranged continuously from 35-45 (in our 0-100 real-life scale). With sRGB, this continuous spectrum would get flattened to one of two tones: everything from 35-40 gets mapped to 35, everything from 40-45 gets mapped to 45. What about Adobe RGB? Each discrete values takes big jumps within the spectrum, since it has to cover a much wider spectrum with the same number of points. So for this flower petal, its *entire* 35-45 spectrum gets mapped to the same value: 40. We get no detail for this flower, since everything maps to the same color.

  • Paul

    I quite like the points Nathan's making, though essentially it is a repeat of the article section on the shades of blue. That part of the article helped me understand this issue far better than a lot of other material I've read.

    The other thing I'm not clear on is the gamut of the device you are using to edit your picture. If the monitor you are viewing it on cannot display the range of colours in the colour space you are using, then whats the point? I think ProPhotoRGB must be far larger than your average monitor, I'm sure one can spend thousands on a higher spec monitor, but that is likely beyond the realms of the majority. I suppose my limited understanding of the topic is questioning why should we work in a colour space that we can't see the full extent of?

  • Paul

    I quite like the points Nathan's making, though essentially it is a repeat of the article section on the shades of blue. That part of the article helped me understand this issue far better than a lot of other material I've read.

    The other thing I'm not clear on is the gamut of the device you are using to edit your picture. If the monitor you are viewing it on cannot display the range of colours in the colour space you are using, then whats the point? I think ProPhotoRGB must be far larger than your average monitor, I'm sure one can spend thousands on a higher spec monitor, but that is likely beyond the realms of the majority. I suppose my limited understanding of the topic is questioning why should we work in a colour space that we can't see the full extent of?

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  • MSM

    Paul, maybe we should work in a colour space that we can't see the full extent of because we will probably be able to enjoy it in the future when technology has improved. For example, I'm glad that plenty of old movies can be transferred to HD-media (Blu-ray, HDDVD) in high quality, even if there were no HD-capable TVs at the time of filming and not many people (if any) could see the movies as sharp as we now can.

  • agrahamt

    I found this because Photoshop CS5 has a feature that allows you to save as srgb in the script menu when saving all the files in a folder as jpgs before publishing them to the web.
    Appreciate this article very much.

  • http://twitter.com/ldexterldesign Lewis Litanzios

    Good work mate. I’ve posted a comprehensive review of a related topic: http://www.ldexterldesign.co.uk/2011/01/taming-adobe-colour-settings-for-your-web-browser/

  • Shutterbugz

    I always shoot in RAW, so the color space is pretty much irrelevant. I want to be able to tweak my files before I commit them to being viewed by others. When I save my finished work, I save them in the appropriate color space for the medium chosen.

    Some people are snapping shots on a deadline. They don’t have time to manually process images, so having the camera do the processing works fine most of the time.

    Occasionally I’ll instruct the camera to write both raw and jpg files, mostly so I can compare my visual acuity and color perception to what the camera thinks and renders. For the most part, the camera does a pretty amazingly good job. It’s been helpful in situations with strange combinations of tungsten, mercury, sodium, florescent and flash lighting.

    There are many excellent places to find discussions on color management. Luminous-Landscape.com and FredMiranda.com are good places to start.

    Michael Zhang should have written an article titled “Why you should probably shoot RAW”.

  • http://www.mattdipasquale.com/ Matt Di Pasquale
  • Anonymous

    Lol! What’s a ‘mundane’ photographer? And what does that have to do with color space. Henri Bresson did not shoot in either sRGB or Adobe RGB. Hilarious.

  • Karl Connolly

    Lots of folks missing the point here. sRGB can change (often dramatically) the look of a finely produced image in adobeRGB or ProPhoto. Simply converting from a larger color space to a smaller one is not the solution, it’s the problem. In so doing you risk clipping large swaths of color from the image. I shoot architecture professionally and increasingly I find I’m producing separate files for print and for web for each image. I find it a tad ironic that digital color space (web) continues to be well behind the scope of even the most basic printer….here’s hoping sRGB grows its boundaries soon!!!

  • http://tommyscapes.com/ tommyscapes

    I’ve discovered problems in editing in sRGB, digital artefacts have been created that editing in Adobe RGB or Pro Photo RGB avoided. I have to convert to sRGB afterwards and ensure it is tagged, but even then I see colour inconsistencies across different software and browsers when viewing with my calibrated wide-gamut monitor. This is an issue with my monitor, and perhaps other wide-gamut monitors and the inconsistency of sRGB signals that different software and browsers send. In short I don’t think anybody who is serious about colour and wants quality results should accept sRGB as the ‘standard’, for my use it simply isn’t good enough. You can see comparisons between workflows on my site (in my profile). Monitor colour space needs to evolve in the same way that resolution and HD content and viewing has.

  • MathH

    Because it’s stupid and there is no reason, but that is the standard of every internet opinion. “Adobe RGB looks far better and everyone wants it in a TV, films and also everywhere else, but you have to CALIBRATE it, and SRGB also has to be calibrated, but you know, whatever, use it instead, it’s some stupid crap to talk about if nothing else”.

  • bcarey

    My pictures always look better and display more consistently if I save them as RGB for websites, not sRGB. I have encountered no problems with how they are displayed in any browsers. When I was saving them as sRGB, they didn’t look anywhere near as good.