Classic histogram shapes
Here are some formations you can expect to see often, and what you can do about them
In this example, the histogram is positioned towards the centre and the left (dark) side of the graph – but with a pale subject, the histogram should be towards the (right) side of the graph. To fix this, use positive exposure compensation or alter the aperture, shutter speed and/or ISO when shooting in Manual mode. (See the opposite page for more details.)
Low contrast 3
The histogram reaches neither end of the scale and is humped towards the centre of the graph. If you shoot raw files rather than JPEGs, you could try ‘exposing to the right’ to push the histogram further to the right-hand side, and then reduce the exposure to normal when you process the image. The reason for doing this is that more picture detail is recorded in the right of the graph.
With a dark subject, the histogram should be weighted to the left, but here it’s pushed beyond the right side of the graph. As we saw last issue, cameras can overexpose dark subjects and make them look too bright, but you can return things to normal by dialling in negative exposure compensation or changing the exposure settings in Manual mode.
High contrast 4
A high-contrast image will show a histogram that peaks at each end. Landscapes are a classic high-contrast subject. In extreme examples, such as this backlit shot of a tree, the histogram is pushed off each side of the graph. To reduce the contrast, you could use flash to light the subject, or take a sequence of shots at different exposure and blend the images later in your editing software.