Like many digital camera images, the shot we’re starting with looks a bit flat, even though the histogram shows a full range of tones. Our fi rst attempt at adjustment uses an ‘S-shaped’ curve which darkens the shadows slightly and lightens the highlights but, because the curve is steeper in the centre section, it adds contrast to the midtones. Our final example is more extreme. It exaggerates the contrast in a specifi c tonal range – the red brickwork.

The way to do this is to open the Curves dialog, then drag the mouse pointer (it changes to an eyedropper) over a critical area of the image. The tones at that point are displayed on the curve as you drag. This is the point on the curve where the curve gradient needs to be made much steeper. Note how increasing contrast also increases saturation. The two are inextricably linked, and if you sort out your image’s contrast properly, you’ll often fi nd out you don’t need to increase its saturation.