Beecher's Handouts /

Setting Exposure / 13.8 - How to Use Histograms

You can use histograms to judge exposure.

Here's the normal exposure for the castor bean leaves.

The next histogram shows pronounced overexposure.

Note the tall spike at the right side of the histogram.

The spike is called clipping.

Clipping means that available image data has not being recorded.

The next histogram shows severe underexposure.

Note the tall spike, now at the left side of the histogram.

Again, the spike represents clipping.

Image data has been lost.

You can also use histograms to evaluate the contrast of a scene.

This photograph of a white CD has tall dark and bright areas.

There's lots of contrast.