Targeted colour corrections

Why let poor colour spoil a great shot? Martin Evening shares his colour-correction know how

Computer colour expert, the late Bruce Fraser once commented that Photoshop’s colour management was ‘push button simple’ so long as you know which of the 26 buttons you had to press and in which order. Thankfully, the colour-management system in Adobe programs is now much easier to work with. Even so, successful colour management will always be dependent on the quality of the viewing hardware. As with most things in life, you get what you pay for. Therefore, the choice of display is important, as cheaper monitors won’t help you to accurately judge the colours you see on the screen.

On a good-quality, well-calibrated display what you see should be what you get, which means whites and greys should appear neutral. But if in doubt there is a simple way to confirm and that is to check the numbers. Regardless of the RGB colour space you are working in, even Red, Green and Blue values will always equal grey. It does not matter if the whites appear to have a bluish tint on the screen. If the numbers are the same, you’ll know they are neutral white really. Therefore, the best way to colour correct any photograph is to look for areas of neutral colour and ensure the numbers confirm this. For example, when working in Camera Raw the White Balance tool can be used to define the white balance based on a sampled colour. Do that and all the other colours will fall into place to display a colour-correct image on the screen. The reason why this works so well is because the Camera Raw database is able to calculate the spectral response for all supported cameras at any white balance setting.

If working in Photoshop with a non-raw file, such as a scanned TIFF or JPEG, you are best off using a Curves