Exposure Basics Explained
Don’t trust the camera’s rear screen to provide an accurate indication of an image’s exposure – its brightness can give a false impression. Instead, call up the histogram…
If the histogram is concentrated on the left side of the graph, this is an indication that the picture is darker than midtone.
If the actual scene or subject isn’t meant to be dark, this means the photo is under-exposed.
If the histogram is jammed against the right side of the graph, this shows that the shot is very bright, with clipped highlights.
If the scene or subject isn’t actually this bright, the photo is over-exposed.
A histogram that stretches the full width of the graph without butting up against either side indicates that the image has the widest possible tonal range, with a full range of shadows, midtones and highlights.
Note the slight clipping in the shot above – the patch of bright sky in the centre of the frame.