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The other day I had a discussion about whether to use the "standard" sRGB color space or a larger color space for my digital photos. My thinking was that because my monitors are limited to sRGB (or less) anyway, I'm not going to see any colors that fall outside what an sRGB file can encode. So there's no immediate need to use a bigger color space such as Adobe RGB 1998. Here's the same photo taken with my Nikon D7100, the left one using sRGB and the right one using Adobe RGB 1998 (they are mousoverable):
(If you have a screen that doesn't do better than sRGB and your browser and operating system do proper color management, the colors in the two photos should look identical. If the right one looks duller, your software doesn't do proper color management. If your screen is better than sRGB and your software does proper color management, the colors in the photo on the right should look more saturated.)
(I actually had a hard time making sure the files are really different. They are. Use Firefox and the setting gfx.color_management.mode = 0 in about:config as explained here, restart Firefox, load this page and you'll see.)
I could of course use Adobe RGB anyway in anticipation of better hardware in the future. The trouble is that not all hard- and software uses color management properly. If something along the way then interprets an Adobe RGB file as an sRGB file, the results will be worse.
Anyway, I then looked at what the JPEG and raw files that come out of the camera look like. The camera can record more color information than what can be stored in a file that uses an sRGB color profile, so when creating an sRGB JPEG file, the camera must reduce the color gamut somehow. The camera can also produce raw files, which is basically a dump of the data straight from the image sensor. Preview, Apple's image viewing/conversion tool, interprets those files as Adobe RGB 1998, but then of course also has to reduce the color gamut in order to display the file. And it does that very differently from how Nikon does it:
So it looks like Nikon just dials down the saturation of the colors, while Apple "clips" the very saturated colors that fall outside the sRGB color space. It's hard to say which approach is superior, but they are very different.