When I started photography, I didn't notice there is a setting called color space in my camera menu. And when I finally saw it, it started confusing me even more. I googled online many many times trying to figure out what color space works best for me and how it is used to render a picture. It really took me a while to figure everything out. So I wrote this post hoping it will help you if you have the same questions.
What is color space?
The short (and simple) answer is that color space defines a range of colors that a picture can render. There are three color space out there: ProPhoto RGB, AdobeRGB, and sRGB. The only thing you need to remember here is that ProPhoto RGB represents the widest range of colors, AdobeRGB comes the second, and sRGB can represent least amount of colors among the three. With that being said, a picture in ProPhoto RGB color space has largest capacity to contain most color information while a picture in sRGB contains the least.
AdobeRGB is always better than sRGB?
So far it may look like the best way is to shoot with the widest color space that your camera supports since it can contain most color information. However, we have to take another factor into consideration that is compatibility. For example, at the time of writing, not all Internet browsers can handle AdobeRGB correctly, not to mention ProPhoto RGB. Although Chrome, Firefox and Safari all claimed to be color managed, meaning they can render in AdobeRGB if the image has an embedded color profile, you can't guarantee the viewer of your photos is using the latest version of one of those browsers. (In fact, I have noticed Firefox renders colors most accurately while Chrome still having a subtle color inaccuracy under some circumstances) If the program is not color managed, images in AdobeRGB will be treated as in sRGB and become terribly rendered. On the other hand, sRGB is the default option for most applications which gives your photos a consistent look across the Internet.
Notice the color shift below. The first image is displayed by a color managed application and the second is not color managed.
Other compatibility issues with AdobeRGB might occur with monitors and printers. Not all monitors can cover AdobeRGB range. Most likely an average consumer is using a monitor only covers sRGB. Similarly, not all printers support AdobeRGB. In fact, most commercial printing labs, for example Mpix, require images in sRGB color space. Smugmug, a popular photo hosting website will convert your photos to sRGB upon uploading.
AdobeRGB has a wider range of colors but it might have rendering issues with browsers and other applications. sRGB has a narrower range of colors but it is Internet safe. With that said, in your camera setting, which color space should you choose?
What if I shoot RAW?
The answer to that is it does NOT matter if you shoot in RAW format. The RAW file that your camera has created is a collection of data that captured by the sensor. It is not yet a photo until you convert it to. In your camera setting, no matter you set it to sRGB or AdobeRGB, it won't be applied to the RAW files just yet. The color space applies when the RAW file is being rendered as a photo. It is during this rendering process that the data in the RAW file is mapped to colors according to the provided color space.
My workflow is to shoot in RAW and import RAW files into Lightroom. In Lightroom the RAW files will be rendered as photos that I can see. This is when color space comes in. Lightroom uses ProPhoto RGB to render RAW files regardless of camera settings. After I finish post-processing, Lightroom allows me to export photos in whatever color space I want. That is to say, the color space option in my camera setting is totally irrelevant because it never touches my files. If you don't use Lightroom, it's fine too. Which color space to use is defined by the software you use to render RAW files. As long as your files stay in RAW format, color space has not yet been attached.
What if I shoot JPEG?
If you don't shoot in RAW, you shoot JPEG instead, then you need to consider what color space to choose in your camera setting. After you click on the shutter-release button, your camera converts the data captured by the sensor to a JPEG photo and save this photo onto SD card, which means the conversion is now done within your camera. So you need to tell your camera which color space to use.
But do you really want AdobeRGB if you shoot JPEG? Probably not. If you really care about image quality and color details, you definitely want to shoot RAW since it gives you so much more control on the image and it allows you to apply any color space you want afterwards. If you don't do any post-processing at all, you just want a JPEG photo straight out of your camera, most likely you don't want AdobeRGB in your camera setting either. Think about what you would do with your photos. Upload to Facebook? Import them to your smartphone? Send them to printers? Then think about the incompatibility issues with AdobeRGB that I just talked about above. Yes, you can always convert AdobeRGB photos to sRGB since the latter is smaller but that takes an extra step.
I set the color space option in my camera to sRGB because 99.9 percent of the time I shoot RAW so this option doesn't matter. Under very rare circumstances I do want to shoot JPEG because I know for sure I won't do any post-processing. In that case, I want my photos to be Internet ready straight out of my camera.