## Colour management: fine tune your kit for the most accurate colours possible

Our colour calibration tips explain how to get accurate colours in your photos by following a few simple rules of colour management.

Producing a colour print that closely matches what appears on your computer screen is something anyone can master if they understand the principles involved and have invested in the kit needed for producing accurate colour. Discover how easy it can be to turn out predictable and pleasing results.

### Colour calibration: An Introduction

In our experience, the idea of a ‘colour space’ is what drives most people crazy as they begin in colour management.

Any colour can be represented as a point in space inside a sphere (see the diagram below). Somewhere within that colour sphere sits the position that describes your chosen colour. It can be represented mathematically as a point on three axes within the sphere. A colour space describes the size and shape of a 3D box that sits within the sphere.

If any of your colours are too strong for your chosen colour space then they’ll simply spill outside the box and that’s called ‘being out of gamut’. In digital photography there are two common colour spaces: sRGB and Adobe RGB.

The first is the default colour space used by most digital cameras and the default colour space of most computer monitors. Both sRGB and Adobe RGB use red, green and blue to reference colours.

However, colour inkjet printers use a combination of cyan, magenta, yellow and black inks. This is because if red, green and blue inks are mixed on paper the result is a horrible muddy brown mess.

In order to translate the colour that appears on your camera’s LCD or your computer screen, we need colour management. In practice, this is really just complex arithmetic that calculates instructions for a printer to place dots of yellow, magenta, cyan and black ink on paper in order to mimic the red, green and blue colours that you see on screen.

With the best will in the world, there’s no way that a series of ink droplets can exactly match the colour that appears on your computer screen, but we can get very close indeed – and we do this by
using colour management.

Once you’ve profiled your monitor and printer using the methods on the next pages, you can then make a test print of one of your photos to compare what appears on the screen and what comes out of the printer.

Before you do that it’s important to understand how light can wreck your colour perception. It’s no good trying to assess your colour prints under the light of a tungsten table lamp or by the flicker of a fluorescent tube. Use daylight to assess your images and you’ll see the real colours.

When you hold your test print up to your computer screen for comparison, it’s important to realise that you’re never going to see a perfect match.

A screen that uses red, green and blue dots of light to create an image can never exactly match the reflected light from a piece of off-white paper that’s covered in droplets of cyan, magenta, yellow and black ink. But with good colour management, you can get very close.