RGB Vs sRGB

I was recently asked what the difference was between RGB and sRGB colour spaces and, although I had a vague idea about it being something to do with printing and monitor screens, I was pushed to give a definitive answer. So, with a bit of research I can now give an answer to that question.

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In your camera menu settings, you may find an option called colour spaces, this setting gives the possibility to use either RGB (Red, Green, Blue) or sRGB (standard Red, Green, Blue) but which one should you choose? Also this only affects JPEG's out of a camera and not RAW files so if your shooting in RAW it's the post processing where you can make that decision. First, we’ll have a look at what a colour space is and how the two RGB groups fit into it. Simply put a colour space is the range of colours that can be used to make up an image. In a JPEG, this can be up to 16.7 million colours that can be represented although, a JPEG is unlikely to contain that many in either colour space. Within the colour space lie the RGB and sRGB colour gamut’s, RGB has about a 15% broader range of colours to choose from giving a more saturated look and because of sRGB’s narrower gamut, colours would seem muted in comparison. So, the conclusion would seem to be go with RGB in your camera or post processing, it has the broader range and photos would look more colourful but, as with all things it’s not that simple.

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Our second point to look at is, where are you going to use your photos? The sRGB colour space was the first to be developed, put forward by HP and Microsoft in the mid-90s for use in monitor displays and since then has become the standard colour space for everything from video games to mobile phones. RGB came later and was Adobes attempt to replicate a printers CMYK colour space on a computer display. With this in mind sRGB would seem the best bet for putting photos on the internet and RGB for printing. This is true in some ways especially for uploading photos to the internet, the problem lies in the printing process, which colour space is being used by your printer or printing company. Having a look at my home printer the default setting is sRGB with the option to switch to RGB if needed. As I only print the occasional photo there’s no real need for me to change the default. However, when I send my photos to DS colour Labs for printing I have to use their colour space which also happens to be sRGB. Personally, for my photography then I’ll stick with sRGB for the moment.

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A few things before we finish, if you decide to use the RGB colour space it is possible to downscale it to sRGB but not the opposite way about. You can future proof yourself, say for use in printing, by shooting in RAW, this can then be used in various ways and if using Lightroom or similar, your still able to export it with either the RGB or sRGB colour space. If your using sRGB now or, maybe by default and your happy with the way images look there’s no reason to change, the benefit would be a faster workflow not having to remember to convert from one profile to another. For most photographers sRGB is going to be fine especially if your photos are JPEG and going onto the internet. Shooting in RAW gives you the best advantage of choosing your colour space when post processing and,checking your printing options could be a start to making your own decision.