Using your cameras histogram to take better photos

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Have you ever wondered what that moving graph on your camera screen means? In the world of passionate photography full manual mode is the norm. As you move away from the “auto” mode in your camera the histogram is an important concept to familiarize yourself with, this article explains the histogram and how it can be used to improve your picture taking skills.

Histogram basics.

A Histogram reveals the degree of image exposure showing proper exposure, it also shows if the lighting is flat or harsh and possible adjustments that will work best. Mastering the art of histogram photography greatly improves your skill not only as a photographer but also on the computer editing.

Over and under exposed
The histogram shows what the sensor is capable of detecting in the shot.

Histogram Geek Talk.

A Histogram is a guide graph counting pixel distribution between black(located on the left end) and white(located on the right end). Darker images move an image to the left while lighter images move it to the right. The height distribution of a graph depends on the number of bright pixels at a point. Color histograms for color photography have three separate (RGB channels) histograms which aid in determining correct exposure instantaneously. For most shooting modes, the combined histogram is more than enough.

3 Seperate RGB histograms are great for advanced users but most situations the combined white graph is enough.
3 Seperate RGB histograms are great for advanced users but most situations the combined white graph is enough.

The horizontal axis.

Represents images maximum potential tonal range (the region where most brightness values are present) or contrast (the measure of the difference in brightness between dark and light scenes).

A pixel in an image can be set from pure black (0) to pure white (255) depending on the level of brightness. The histogram horizontal axis documents levels of brightness and their distribution.

The vertical axis

Represents the number of pixels with each of the 255 values of brightness. The higher the line from the horizontal axis, the higher the number of pixels at that level of brightness.

How to use a histogram to take a better photo
Look at the distribution of the histogram pixels though your eyes are the final determinant.

  • Use exposure compensation if most pixels are towards the left(darker) to increase exposure.
  • In an event of many pixels towards the right (lighter) use exposure compensation to reduce exposure.

Photos look best when the images are using the entire tonal range.
Pixels collected in one area in the histogram lack contrast between the darkest and brightest areas this can be edited in photo-editing software using commands that spread pixels to the entire tonal range.

Clipping

A clipped pixel is a pixel showing at the extreme ends with levels beyond 0 and 255 hence tones are lost or “clipped” in the image. This means some parts of the photo are either too bright or too dark for the camera sensor to record any detail and would appear as a black or white area in the photo.

Avoid clipping by using the highlight warning setting during image composing. Check your camera setting for this warning function.

An example of clipping, in this photo the sky and some stones are too bright and can not be detced by the sensor so are just totally white. The red indicates the areas that are clipped.
An example of clipping, in this photo the sky and some stones are too bright and can not be detected by the sensor so are just totally white and have no detail. The red indicates the areas that are clipped.

Adjust exposure to reduce clipping

The easy way to remove clipping is to adjust the exposure,

  • UNDEREXPOSURE Black Clipping – By increasing exposure, you shift the histogram to the right.
  • OVEREXPOSURE White Clipping – Decreasing exposure moves the histogram to the left.

The aim should be to have the least about of clipping as this will give you much more room to play around with in any editing software.

Using your histogram

You can’t always get it perfect.

If you are shooting in a situation that you can not avoid clipping such as a bright sunset or at nighttime with a bright light or dark area your camera sensor is not capable of capturing the whole tonal range, so no matter what exposure settings you choose you will always have clipping.

To minimize this you can use HDR to take 2 or more photos at different exposures and merge them together to make a photo with a wide exposure beyond what you can capture in one shot. If you are in a studio or professional setup you can just add or remove a light in certain places to balance the brightness across the whole scene.

Scenes like this have a wide tonal range greater then 255, by spreading the detail across 3 images we can capture more details.
Scenes like this have a wide tonal range greater then 255 so you can not avoid clipping, by spreading the exposure across 3 images we can capture more detail and blend them together into one HDR image.

You may have noticed this function in your phone too, and it widens the detail you can get in a single image, if done correctly this can allow you to capture the full spectrum of detail in a picture.

We will touch more on HDR in a future article as there are a lot of options on how to create and take wide dynamic range photos.

If you are after some camera accessories to upgrade your shooting abilities check our range out and if you have some other tips on making the perfect shot leave a comment and share your experience.