Camera Histogram Explained for Beginners

Michael • updated June 29, 2022 • 8 min read

Camera Histogram Explained for Beginners

One of the best things about digital photography is the histogram, which can be a little scary for people who are just starting out. But there’s no reason to be afraid of it. Once you know how it works, it’s pretty easy to use.

Before digital photography, we had to wait until the film was developed to make sure the exposure was right. With the help of the histogram, you can see this information before you take the picture (if your camera has an electronic viewfinder), after you take the picture, and also when you are editing the picture.


 

What is a camera histogram?

Camera histogram explained. the histogram is a graph that shows how dark and light tones are spread out. Simply put, how light or dark are your image’s pixels?

The X-axis shows the brightness of the tones from left to right, and the Y-axis shows the frequency distribution from top to bottom (Y-axis).

“The histogram shows in a graph how the brightness values are spread out, from pure black to medium gray to pure white.”

Here, the darkest values (called “lows”) are on the left, and the brightest values (called “highlights”) are on the right. In the middle, you can see tonal values with a medium amount of brightness.

If you can see a high deflection in an area near the top, it means that this area has a lot of tone values of the same brightness.

B/W histograms and colored histograms

In some cameras or in image processing, the histogram is also divided into its color channels: red, green, and blue. The histogram is thus supplemented by the information that certain colors occur at a certain brightness.

Camera histogram illustration with correct exposure

What are some of the benefits of using the histogram?

  • The histogram is great to determine how well the image is exposed.
  • Taking a picture in bright sunlight is a good example. If there is a lot of bright light, you won’t be able to tell from the camera’s screen if the image has been exposed properly.
  • When editing photos on a cell phone, the same rules apply: Depending on how bright your screen is set, your image will look the same way. If you use a different smartphone to look at the picture, it will suddenly look darker or brighter.
  • Because of this, always use the histogram in Lightroom Mobile on your phone.

How to read a histogram?

In the image below, you can see the balanced histogram of an optimally exposed image: The tonal values are distributed over the entire histogram.

Camera histogram illustration with underexposed

1. Underexposed photograph

The first third of the histogram is very skewed, but it flattens out a lot as you move to the right. The picture is underexposed because most of the tones are dark.

Photography tip:

  • In manual mode, you need to increase the aperture, exposure time, or ISO to let more light into the camera.
  • Check that the exposure compensation is set to +-0 EV. If you don’t, the automatic will expose your photo wrong.

How to edit images:

  • First, raise the overall exposure, and then make the depths lighter. This only works up to a certain point, though. When processing an image, if you brighten it too much, you’ll see clear noise in the dark parts.
  • In the worst case, the dark parts of the picture are “washed out,” which means they have no details and are just pure black.
  • A picture that is too dark has one benefit: it is easier to save than a picture that is too bright. When there is a lot of light, it is easier to lose details.

    So, set your exposure compensation to -0.3 or -0.7 EV and underexpose your photos on purpose.

2. Overexposed photo

The right third of the histogram goes up a lot, and the left third goes down sharply. The mountain goes all the way to the left side of the graph. Most of the tones in the picture are bright, and there aren’t many dark areas.

Camera histogram illustration with overexposed

The parts of the clouds that are very bright are “burned out.” That means they no longer have any details and are just white.

The right part of the histogram shows it. The “mountain” of tonal values is close to the right edge, and many of the pixels are pure white.

Photography tip:

  • When taking a picture, you should always look at the brightest parts because they lose detail the fastest.
  • You can try out the “Zebra” setting on the camera. If you have Zebra turned on, Live View will show “zebra stripes” over areas that are too bright.
  • The stripes show that it’s hard to tell what’s going on here. You can fix the problem by using the exposure compensation to deliberately underexpose your image (about 0.7 EV – 1 EV).
  • When the dynamic range of the camera is too low, details are often lost. This means that the camera can’t take a picture of both the brightest and darkest parts at the same time.
  • If you shoot in RAW, the dynamic range will be wider, making it more likely that you can save burned-out areas.

How to edit images:

  • Always start with exposure to get the right balance of light and dark in the middle.
  • Lessen the highlights in bright areas to bring back details. Use a graduated filter that you drag into the image from above to only change the sky. It needs a little less exposure and a little less brightness in the highlights.

3. Color cast

The histogram shows that the numbers are spread out evenly across the whole width. In the right third, there is a yellow slope that starts to show.

Camera histogram illustration with color cast

If the histogram shows the color channels as well, you can also see color casts and how the colors are spread out.

Photography tip:

  • To fix color casts better, use auto white balance or shoot in RAW.

How to edit images:

  • In the picture above, the yellow color channel is very strong, giving the picture a yellow tint. To get rid of the yellow tint, you need to bring out the opposite color. Changing the white balance to cool gets rid of the color cast. Green/magenta color casts work the same way.
  • The worst thing about a color cast is the color that goes with it.
    So, the graduation curve is a good way to get rid of color corrections. In the picture above, you would have to choose the blue color channel and boost the blue tones in the highlights (and thereby weaken the complementary color yellow at the same time).
  • The histogram is usually a good way to change the white balance by hand. If the color channels are close to the same, the white balance should be good.
  • But a change in color is not always a bad thing. There are many interesting ways to use color to give an image a “cinema look.” For example, a slight yellow tint can help set the mood for a sunset.

4. Missing contrast

Contrast describes nothing more than a difference between light and dark. If the image lacks contrast, the histogram looks like this:

Camera histogram illustration with missing contrast

The histogram has a high deflection in the center and flattens out to the left and right without touching the edges.

So, an image with such a histogram consists mainly of middle tonal values – there is hardly any pure white or black. The image looks flat!

So an image with such a histogram consists mainly of middle tonal values – a pure white or black is hardly present. The image looks flat.

 

Photography tip:

  • It is often due to the subject itself when the histogram looks like this. When it’s foggy or raining hard, the contrasts fade. If you want the look, you don’t necessarily need to adjust the image.
  • Direct sunlight on the front lens lowers the contrasts. This is where the lens hood helps you.
  • Loss of contrast can also be due to a dirty front lens, poor lenses, or if you’re shooting through a milky glass.

How to edit images:

  • You should always try to stretch the histogram across the full width in image editing.
  • For proper contrast, you should always adjust the exposure so that the “hill” is in the center, and then get the white and black points right. This will “stretch” the brightness of the image across the full width.

The histogram and its limitations

There are some images for which the way the histogram works won’t help us process them.

On the contrary, if you try to fit these pictures into a “balanced histogram,” they will look terrible.

The following pictures will help make it more clear:

Photos of snow: On a histogram, images of snow always look too bright. If you darken the whole picture, the snow will look dirty and unnatural.

When you take a picture at night or of a sky full of stars, most of the picture will be black. This is common and must be the case.
Fog shots: If you take a picture in heavy fog or rain, the contrast will be lost.

Shots with a high or low key are ones where you purposely underexpose or overexpose the image. You shouldn’t use the histogram as a guide because it affects how the image looks.

In the situations above, you should only talk about your main point. Just move the sliders and ignore the rest of the picture. Look at your subject by itself and adjust the exposure until it looks right.

How the Camera Histogram works when taking pictures?

  • Activate the histogram if you shoot in manual mode. The histogram is shown in a different way by each camera brand.
  • A small histogram in the corner that doesn’t have any color channels works best. A quick look at the histogram is all you need to figure out how much exposure you have and avoid making mistakes.
  • If you are shooting with an automatic camera, you don’t have to use the histogram (e.g. time, aperture, or fully automatic). The automatic setting will try to get a good exposure.
  • If there are a lot of differences in brightness (like a bright sky and a dark landscape), you should use the exposure compensation to let the automatic system underexpose the picture on purpose.

The camera zebra function

This feature shows you part of the image that is too bright and could burn out and lose details. The bright spots are marked by diagonal stripes, which is how the animal got its name “zebra.”

The zebra stripes show the areas that are right next to the white right edge of the histogram. The zebra function can be found in your camera’s settings.

This function is great for taking pictures of landscapes. Clouds that are lit up by the sun burn out quickly. The zebra stripes warn you of danger, and you can do something about it.

Remember this:

  • Show the histogram in your image editing software and watch how it changes as you move the sliders.
  • Look at the histogram every time you shoot in manual mode to avoid making mistakes.
  • Before you publish or print images, you should still look at the histogram. You can be fooled by how bright the screen is.

 

Frequently asked questions


What is the difference between luminance histogram and RGB histogram?

Simple histograms (luminance histograms), like the first two, list the red, green, and blue values for each pixel in an image and show how the total brightness is spread out. Here’s another picture with a lot of colors.

The RGB histograms show how the three primary colors, red, green, and blue, are spread out in terms of how bright they are. Then, the sunset shows a red curve to the right, because the red part of the image is much brighter than the green and blue parts.

If you enlarge the picture, you can see the red peak in the histogram on the right side. It shows that red has reached its brightest point in one part of the picture. This red comes from the sun in the picture.

Where to find the histogram on my camera?

On cameras with a display preview, you can often see the histogram before you take the picture (available on all compact cameras and some newer digital SLR cameras with LifeView technology).

In this case, the display is either split into two parts to show the subject and the histogram, or the histogram is added on top of the image on the display.

However, the display of the histogram must be activated in the settings options of your camera. Please check the camera manual of your camera.

What is a histogram in simple words?

The histogram is simply a graphical representation of the distribution of brightness values according to their number. The higher the graph is in one place, the more pixels of the photo has the same brightness value.

The light tonal values are shown on the right, the dark ones on the left. On the far right is pure white, and on the far left is pure black.


Links to Camera manufacturers:

 

What is your take on camera histogram explained – let is know in the comments!

By Furoore team member Michael
Furoore Team is here to assist you in capturing the most significant moments in your life. To create exciting photographs, discover photography guides, find unique photo ideas, and limitless image inspiration.

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