The advent of the digital age in photography has brought many benefits to photographers. It means that you can take a large number of photos without the price tag of film. You can view the shots you have taken immediately after shooting. You can change the ISO for each shot. With film photography, you had to change the film. But one of the most important advantages of digital photography is something that scares many aspiring photographers at first, and that is the histogram.
But there is no reason to avoid it. Histograms are actually quite easy to use once you understand how they work. A histogram is simply a graphical representation of the tonal range of a photograph that helps you evaluate exposure.
In the days of film photography, one had to wait until the film was developed to know if a good picture had been taken. With a bar graph, this information is immediately available.
How do you read a histogram?
It’s easy. The horizontal axis of the histogram graph represents the brightness of the tones in your photo. The left part is responsible for the darkest tones, the right part for the lightest tones, and the center part for medium brightness tones or called semitones. The vertical axis shows how many pixels of this brightness are in the photo; the higher the peak of the graph, the more pixels there are
The most important thing to know about the histogram is that if the peak touches the right edge of the graph, the photo has a problem. This means that the majority of the image is either overexposed or completely white, with no detail in the highlights. And the biggest problem is that there is no post-processing or anything to do with shooting in RAW because there is no data in the areas that are skipped white. This only applies if the peak touches the edge of the graph. If the peak is just before the edge, it is OK.
If the peak touches the left edge, it means that part of the image is completely black. You can use Exposure Compensation as a plus to compensate for the next shot. However, if you are currently busy shooting at night, such as starry skies, this is a perfectly «sound» histogram for such cases.
There is no such thing as a perfect histogram. It is a graphical representation of the tonal range of an image. What you do with this information is up to you as the artist. The presence of many dark or light areas (provided they are not overexposed or underexposed) is not necessarily a bad thing.
Let’s look at some examples of how histograms look in different types of photos.
Examples of Histograms
Scene shot in high key
Shooting a scene in high key will result in a photo with more highlights and fewer mids and darks. If you want to capture a scene in high key, you will need to shift the histogram to the right, but make sure it does not peak at the right edge. If you want to capture a high-key image but the histogram shows more shading in the center of the graph, the image highlights will probably look grayer than desired.
Pelicans in the Salton Sea, California
Stage in High Key
The histogram of the image above shows that the highlights are predominant.
Stage in Low Key
A low scene is a dark scene obtained when taking pictures at night. In this case, the histogram graph will be shifted to the left. Also, there may be a peak at the left edge. This indicates the presence of the darkest region
In a similar scene, the schedule will be shifted to the left.
The histogram above shows a dark scene.
Very Contrast Scenes
A high contrast scene is one with lots of very dark and very light tones and perhaps not many medium tones. In this case, the histogram climbs from left to right, with a disturbed or even schedule in the center.
Very contrast scene. Extreme light and extreme dark tones and very small tones.
The histogram of a high contrast scene is high.
Low Contrast Scene.
Low contrast scenes (tonally) have medium tones and few bright colors. The histogram of such a picture takes the shape of a bell. Note that in tonally, this is a low contrast scene and the color high — control j
Again, you as the artist decide what to do with this information and whether or not to use it. This is another tool in your arsenal to help you turn your artistic vision into a great picture.
If you are not satisfied with the histogram of your image, use exposure compensation. With its help, you can adjust the exposure by making the image darker or brighter. Or you can use a flash, reflector, or diffuser to affect the lighting of the scene in another way. The choice is yours.
Understanding Color Histograms
In the example above, you noticed that the histogram not only displays the brightness of the shades of gray, but also the color. Yes, it could be overweight or undercolor! Sometimes there is a color that comes out very bright in a photo, but this color is very rich and may lose detail. This usually happens with reds, for example.
How to deal with this? The easiest way is to slightly bleach this particular color during post-processing to return some of the petal areas. The histogram above shows the increase in red tones in the lighter color zones.
When to Use the Histogram
You can combine the histogram directly with the Live View mode while shooting (when using a mirror camera) to view it before taking a picture (or simply turn on the histogram display on the LCD screen if you have a Celert camera) . You can also view the histogram after the toga. In any case, it is important to use the histogram to control the correctness of the exhibits displayed while shooting «in the field. Thus, there is an opportunity to traverse the frame while at the desired location.
You should not rely on visual inspection of the shot photo on the camera’s LCD screen to assess exposure correctness and turn on the histogram. This should be done because the brightness of the LCD display has nothing to do with the brightness of the photo.
The histogram can also be used in any graphics editor to process the photo afterwards. Use it to see which settings need to be modified so that they are not too bright or too dark in the image during processing.
Hope this gives you the best idea of how to use this useful tool. If you have any questions about the histogram, please describe them in the comments.