How to Use the Histogram in Photography for Better Understanding and Editing

In daily shooting, many people encounter this situation:

The photo on the camera looks normally exposed, but after exporting the photo, it is found that its real form is quite different from the presentation effect of the camera, and there is obviously a problem with the exposure.

Due to factors such as ambient light and screen brightness, this situation is relatively normal, but it also brings us an inspiration: when looking at and analyzing photos, we must learn to look at the histogram.

So, what is a histogram?

Simply understood, a histogram is a display form of the brightness distribution of photo pixels:

Horizontally, a histogram can be roughly divided into three parts, the left side is the shadow area, the middle is the middle tone part, and the right side is the highlight area; the far left is the dead black area in the shadow, and the far right is the overflow area in the highlight.

Vertically represents the specific distribution of pixels. For example, if the hill on the histogram is concentrated on the left side, it means that a large number of pixels in the photo are concentrated in the shadow area, and the whole is relatively dark, and there may be a situation of under-exposure; if the hill is concentrated on the right side, it means that the photo is generally brighter and there may be a situation of over-exposure.

Therefore, when viewing a photo, we can call out the histogram on the camera and more accurately judge whether the photo is normally exposed according to the distribution of pixels on the histogram.

Of course, according to different themes and creativity, there are different standards for normal exposure, and the histogram is just a reference for us.

But we can pay special attention to the dead black and highlight overflow parts, that is, the far left and far right sides of the histogram. If there are a large number of pixels distributed in this part, then there is a high possibility that there will be obvious under-exposure and over-exposure situations in the photo, and we need to adjust the shooting in time.

In addition to reflecting the exposure situation, the histogram can also give us a reference for the light and dark contrast of the photo:

We still regard the histogram as three parts: shadow, middle tone, and highlight. If the pixels are evenly distributed in all three parts:

Then it means that there are shadow, middle tone, and highlight forms in the photo at the same time, and there is a certain degree of contrastivity, just like the following photo:

And if the pixels are mainly concentrated in the shadow and highlight areas:

It means that the contrast of the photo is very high, and the light and dark contrast is very large, just like the following effect:

Conversely, if the span of the pixels in the photo is very small and only concentrated in a certain area, then it means that the light and dark contrast in the photo is very small and the pixel distribution is very uniform:

From here, it can be seen that the histogram can bring great convenience and reference to our post-processing. When we adjust some parameters, the histogram also changes accordingly.

When we increase the contrast, the light and dark contrast of the photo is enhanced, and the pixels on the histogram will move closer to both sides; when we increase the shadow, the pixels on the left side of the histogram will move closer to the right side; and when we increase the exposure, all the pixels on the histogram will move to the right as a whole.

According to this property of the histogram, we can easily analyze the light and shadow characteristics of a photo.

When we encounter a photo we like, we can first call out its histogram, and then imitate its light and shadow effect according to the reference of the histogram, so that we don't have to painstakingly ask for parameters and filters, because the inside story of the photo has already been completely exposed by a small histogram.

In terms of color as well, some post-processing tools such as Lightroom can not only display the light and shadow histogram, but also reflect the color characteristics in the form of three primary colors, and the principle is the same as that of light and shadow.

From this, it can be seen that as long as we can read the histogram, we can almost copy and simulate the style of most photos, and our understanding of shooting and post-processing will also have a qualitative breakthrough.

That's all for today's content.