What Is a Histogram?

A histogram is a graph that shows how the brightness levels of a photograph’s tones are distributed. This simple idea has revolutionized the way photographers approach exposure because it removes the guesswork.

Image

Why Cameras Have Histograms

The reason your camera displays a histogram is quite simple—it’s the only way of determining the accuracy of your exposure. Don’t make the mistake of judging exposure by looking at your photos on the camera’s LCD screen. That doesn’t work.

If you’ve ever tried to look at the screen of a laptop computer outside, you’ll understand why. Your perception of the brightness of the image on the LCD ...

Get Exposure and Understanding the Histogram, Second Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.