Ever wondered why your images don’t look the same on your monitor and in Photoblog? The short answer has to do with how colours are recorded, mapped and shared between your monitor and the and the web.

This is known as the “colour space” and is rather like a box of crayons available for ‘painting’ on your screen. If you use a compact, a low-end dSLR or shoot always in JPG, it’s a fair bet your camera is using a colour space known as sRGB, i.e., a set of colour combinations based on Red, Green and Blue (some people say the “s” stands for “stupid”). There is a finite combination of colours: 216. It should be 256, but Windows and Mac systems on the web see only 216 in common. The translation from broader colour spaces to sRGB often results in dull reds.

For a workaround, see this post.

If you have a dSLR, you can set it to Adobe RGB 1998, a broader colour space (a.k.a. a “gamut”), which I strongly advise you to do. Benefits include a truer representation of colours, greater vibrancy and more depth.

This applies only to viewing images on the web. There is usually no need to convert colour spaces for your printer (which uses the CMYK – Cyan, Magenta, Yellow and blacK – colour space and automatically converts for you).

ProPhoto colour space is used natively by Adobe Lightroom and offers the best reproduction for serious, high-end cameras and applications. The downside is much larger files, which you have to convert manually. You won’t really notice a difference between Adobe RGB and ProPhoto unless you have a good (read “horribly expensive”) monitor.

Below is a diagram from Gerry Kopelow, “Architectural Photography”, 2007, which shows the differences.