Adjusting exposure

The shot with the biggest increase in exposure works well – it ‘bleaches out’ a potentially distracting background.

So how precise do you have to be with exposure? Even though digital cameras only have a certain amount of ‘exposure latitude’, in practice there are many different ways of interpreting a scene, and many exposure errors can be rectified or at least improved with a bit of image-editing. To give you an idea of how the subject brightness changes with exposure, here’s the same scene at seven different exposure values, all shot at the same lens aperture, but with shutter speeds 0.5 EV apart; the images also demonstrate the idea of exposure latitude and dynamic range. There isn’t one shot in which detail has been recorded both in the foreground and the garden outside – the scene is outside the dynamic range of the camera’s sensor. You might prefer the ‘overexposed’ shot because it shows the subject’s face with a nice high-key effect, or a darker silhouetted version. Or you might open one of the in-between shots in Photoshop, and attempt to balance the tones more evenly.