Confessions of a Keytarist

This post is a continuation of the second histogram post entitled “The Highs and lows”.

Another important thing a histogram does is describe contrast within your images. According to Wikipedia:

Contrast is the difference in visual properties that makes an object (or its representation in an image) distinguishable from other objects and the background.

Or, in more simplistic terms, Contrast is a measure of the difference in brightness between the light and dark areas of your photographs.
Images with histograms that have broad tonal ranges have a significant, or “high” contrast, whereas images with histograms that have narrow tonal ranges may appear dull or flat and are known as “low” contrast.

Differences in contrast can be caused by any combination of subject matter and lighting conditions. By rule of thumb, images taken in fog will be low contrast and those taken under strong daylight will have a high contrast.

Contrast can have a significant visual impact on an image by emphasizing texture, as shown in the following image:

The left side of the image is a low contrast image, whilst the right side is high contrast. The high contrast water has more pronounced shadows and highlights, which enhances the wavelets and creates an image which “pops" out at the viewer.