In a previous blog post we learned what a histogram is. In today’s post we’ll see how to use histograms to help take properly-exposed photographs. If you haven’t read the previous post, or are not familiar with histograms, I would recommend you read that post before continuing with this one.
A key aspect of good photography is exposure - the amount of light that enters the lens. One of the most useful tools a digital cameras has to help you measure a photograph’s exposure is the histogram. In order to learn how to use it, you must first learn understand what a histogram is.
Let’s pretend I teach a class of 20 students. One day I decide to give the students a test in which they can score anywhere from 0 to 100 points. After grading the tests I want to see how the population of students did. So I graph the scores in a histogram. A histogram displays the distribution of measured values across a population. Let’s make one now.