You may have heard of the term ‘histogram’, but aren’t really clear what it is.
In this article, we’re not only going to explain what as histogram is, but we’ll also show you how to read histogram.
What is a Histogram?
A histogram is a type of bar graph that is used to help photographers obtain the exposure they’re aiming for in a photo.
The dictionary definition of the histogram can be quite confusing, so we’re going to skip that!
Instead, just understand that it is a tool on your camera that will show you the tonal range of the image.
The Histogram Reveals the Tonal Range of an Image
A histogram will show you the shadows and black sections of a photo on the left side of the graph while the middle section deals with mid tones and the right section of the graph represents bright and highlighted areas.
The highest point on this graph means that the specific tone has the most pixels in the photo.
For example, if the highest points of the graph are on the left side, then it means there are a lot of dark pixels in the image. If the highest points are on the right side, then there are a lot of bright pixels in the image.
Photo by Wildshots.ca
A general rule of thumb is that in normal settings if the black or white sides of the graph are high, then the odds are you might not be happy with the exposure. However, if the setting has an abundance of white or black objects within it, then it may be acceptable.
In the majority of everyday photographs histograms will typically show a pretty evenly-balanced tonal spread with the peak being in the graph’s middle section.
If you look at the histogram and notice that the graph does not slope down toward the left or right side, but instead is chopped off midway (clipped), then that it is an indication that the photo is either overexposed (right side) or underexposed (left side).
The histogram is very valuable in this sense because you can’t always tell if an image has been over or underexposed when reviewing it on the viewfinder.
You can turn on the camera’s histogram feature to see the graph for each of your stored images. You can then study it after each photo. Dramatic peaks at either end means there are pure black and/or white pixels and will likely offer little detail in that section of the image.
Of course, an evenly distributed histogram will be hard to achieve if the scene you’re shooting is very light or dark.
If there are gaps on either end of the graph (meaning the histogram does not continue all the way to the left edge or right edge) then it means you can adjust the exposure without losing any detail.
There isn’t really a right or a wrong when it comes to histograms as photos and their exposure are in the eye of the beholder. However, you can alter the exposure to maintain either shadow or highlight detail.
It’s really all in the way you interpret the scenes you’re going to shoot.
Many DSLR cameras come with a highlight warning feature. If you try to brighten your image via exposure it will let you know when enough is enough.
Overexposed highlights will usually cause the camera’s feature to blink or flash when you’re previewing the scene on the camera’s screen. Many photographers refer to this action as the blinkies.
How to Fully Understand How to Read Histogram
It’s may seem confusing at first on how histograms work and how to read them. The best way really is to take several photos and then study the graph to see how the tones are represented.
For instance, take some shots in with similar tonal ranges within the photo, such as a snowman in a snowy field or something such as a black car in front of a black background. You can then compare the histograms against each other.
The more photos you take and check the histograms the more you’ll start to understand them. Once the concept clicks in your mind, you will know instantly how to adjust your exposure when looking at the histogram graph.
We hope you enjoyed these this article on how to read a camera histogram. Now that you’re finished reading, leave a comment below telling us what your thoughts are about this tool.
Then, check out our related posts to learn even more ways to improve your photography.