There’s a section on the menus of digital cameras for histograms and these are basically small graphs. However, many casual photographers aren’t really sure what they’re used for or how to read them. Basically, a histogram can be very useful tool for photographers as they produce a quick summary of an image’s tonal range. The histogram will represent your photo’s tones in a graph with the left side of the graph representing black and the right side of it representing white.
The highest point in the graph means that particular tone has the most pixels in the image. Therefore, if your photo consists of a lot of dark pixels you’ll notice that the graph of the histogram will be higher on the left side. If the image has a lot of lighter tones then the graph will be heavier on the right side.
Because the LCD display on a digital camera is relatively small, there are many occasions when you can’t really review your photos adequately enough until you view them on a larger screen such as your computer’s.
You might have to wait until you get home before you can tell if the picture is under or over exposed.
If you take a quick look at the histogram you’ll be able to tell what the exposure is like instantly and you can adjust your settings if you feel you need to re-take the shot.
However, when it comes to a histogram, there’s not really any such thing as a good one, as beauty is in the eye of the holder. Photographs are often just your personal taste as they’re used for expressing yourself and being creative. The results of the histograms will basically depend on your photography style and your subject for the photographs.
However, in most normal-day photographs you’ll probably notice that the histograms will generally have a pretty evenly balanced tonal spread and the graph will be relatively even across it. You’ll find that the majority of well exposed images will typically peak around the middle of the graph and then taper off at the ends of it.
You can turn the histogram feature on so it will show you the graph on each of your stored photos. This allows you to study the histogram right after you’ve taken a shot. If you notice there are some dramatic peaks in the graph at either the left or right ends then your image has quite a few pixels that are pure white or pure black.
This could be what you’re looking for in your photograph, but just remember that those sections of the photo will likely have little detail. If you didn’t plan on capturing a lot of black or white in the image then the photo could be under or over exposed.
Overall, the histogram is just used as a quick tool to check and see if the image turned out the way you had hoped. It’s a good tool for letting you know how your photos are exposed. Once you learn how to read them and compare them with your photos you’ll be able to decide if you need to take your shot over or if it’s what you had expected to find.