Histograms are graphs. In photography and video the histogram is a graph of the tonal ranges of our image. Each image has its own graph. Certain cameras give you the option to display the histogram next to your image in the image playback mode. Most editing software that accompanies your camera offers this feature. One of best explanation of a histogram appears on Nikon's Learning Center: "You might think of it this way: a light meter reads the scene before you take the photo; the histogram analyzes the photo you've just taken."
What do the histograms tell you?
Luminance histograms show the brightness level of our image. Separate histograms are sometimes displayed for each color channel (red, green and blue.) The luminance histogram is often the most well known.
Bell curve=ideal histogram?
If your luminance histogram is shaped like a bell curve, you usually have achieved ideal tonal range or exposure. If you histogram spikes at the far right of graph, your image may be overexposed or lack highlights. If your histogram spikes at the far left of the graph, your image may be underexposed and lack shadow detail.
High Key and Low Key Images are exceptions?
High key backgrounds are very light. Low key backgrounds are really dark. While these backgrounds causes exposure issues, It would be normal for a high key image to have a histogram with spikes on the far right and conversely a low key image to have a histogram with spikes on the far left.
No perfect histogram
There is no perfect histogram. Try to avoid spikes that touch the ends of either side of the graph as in the histogram pictured. By touching the right end of the histogram, you image will have an area of blown out highlights or a solid white area without detail. Sometimes in the playback mode of your camera you will notice these areas will flash. Perhaps a white shirt on a model. By touching the left end of the histogram, your image will have an area of solid black or a "blocked up area" of shadow detail showing no detail in black areas.
How do I fix problems with the histogram?
In post editing software you will be able to move your histogram to adjust your exposure with some success. Sometimes you will be more successful with a raw image.
For best results and if the opportunity presents itself reshoot the photo. Consider choosing a different metering mode, manually meter, or use exposure compensation. Add +1 of exposure compensation to lighten a image (when histogram spikes to far left). Use -1 of exposure compensation to darken a image (when histogram spikes to far right).
For some more detailed information histograms visit
Zebra lines or patterns in video can help you control exposure while you are taking the video.
For more on zebra lines visit