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CLOSED Assignment: Histograms

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Indy Photo Coach is a group administrator Indy Photo Coach says:

Many of today’s DSLR cameras contain a little-used feature called a histogram. It sounds somewhat forbidding, but it is a great tool to check the exposure of your images.

The histogram is a graph showing you how color is distributed in your image. On the left side of the graph are the dark areas of your image - on the right side are the light areas.

In a properly exposed image, the slopes coming down from the peaks both on the left and right side of the graph drop off and hit the horizontal line in the lower left and right corners of the graph.

In an improperly exposed image, you will see one of two graphs. Either:

* The slopes cut off on the sides.
* The slopes hitting the horizontal line before reaching the sides.

Through trial-and-error, I found if I under-expose my images by 1/3 to ½ stop, I get a better exposure (as shown on the histogram) the first time. Once you learn how to use it, you can tell at a glance if your image’s exposure is correct or over/under exposed.


1) Find an extremely white scene a white-washed wall works great.

2) Meter and shoot an image.

3) Turn on your DSLR histogram feature and view the image.

4) Now adjust the graph by using your exposure compensation feature.

5) Add a stop of light and shoot another image.

6) Remove two stops of light and shoot another image.

7) Now, by using the graph information on the histogram, review each image and watch how the slope lines change in each graph.

By Ron Kness
3:59PM, 25 August 2009 PDT (permalink)

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