Today I want to talk about one of the most helpful features of the camera- the histogram. Don’t think I always liked histograms. When I started, I found them complicated to understand and in fact, I totally ignored them for a while. However, once I saw the point of the histogram, I started checking them on the screen of my camera every time I was taking a shot. Trust me; the time invested in understanding histograms is totally worth it. They will become one of the best tools you will have, both in the field and in post-processing.
The histogram is a graph that shows the range of tones in your photo, in other words, it tells you which shades you have in the photo you just took.
You can set your camera to show you the histogram in its screen each time you take a photo. This is quite handy, especially at the beginning when you are still not used to checking it and you might forget to ask for it. In my Nikon camera, in order to see the histograms in the playback, I needed to check the Histogram in the menu of the Display mode. If you have another type of camera, have a look at the Manual and check how you can set it. It will probably be something similar to what I explained for the Nikon.
Most cameras also have the option to show you the RGB histogram. In fact, this is a group of three histograms, each one showing you the histogram of colors Red, Green and Blue. Today I am going to focus in the general Histogram, but I just want you to know that you have the option to use it by the 3 colors as well, should you choose to do so.
Once you import a photo to Lightroom, you can automatically check the histogram from the Library and Develop modules.
Getting familiar with the histogram
Histograms can look a bit scary at first, but once you know what to look for, they are quite friendly. The histogram is a graph with a horizontal axis which represents the shades you have in your photo. On the left edge you have the pure blacks and as you go to the right on the axis you have lighter and lighter tones until you reach to the pure white in the right edge. I have a little trick to remember where are the blacks and whites in the histogram. I always think the histogram is like “B&W photography”, black is first (in the left) and whites after them (in the right). For this trick to work you have to think from a left-to-right writing mode.
OK, so now we know what the horizontal axis means. What about the height of the histogram? It tells you how much of each shade you have in the photo. The basic principle of reading the histogram is the same; the more peaks you have in one area on the horizontal axis and the higher they are means that these are the tones and shades that are the most dominant in the photo.
Let’s see this in a real photo:
The histogram is a great tool for getting well-exposed images. A general rule of thumb is to have the histogram stretched all over the horizontal axis and avoiding having strong peaks (spikes) at the extreme left and/or right of the axis.
A photo with too many picks in the blacks means that it is too dark or underexposed. To correct the exposure, you will need to increase the light of your image by, for example, using a wider aperture or increasing the ISO.
On the other hand, if the photo has a lot of high picks in the white, it means that it is overexposed or even burnt. This time, to correct the exposure, you will need to decrease the light of your image by, for example, using a smaller aperture or a lower ISO.
Now you know! If you see that your histogram is too much in the blacks or in the whites, this means that you MIGHT need to correct the exposure of the image. Notice that I said MIGHT. Why? Because as photography is a creative craft, it might happen that having a underexposed or overexposed photo is exactly what you are aiming for. You need to think what do you need in your final image and then see if the histogram you have matches what you are looking for. I will show you with a little game!
Let’s play the histogram game!
I am going to show you a histogram and you need to decide which kind of photo might correspond to it. Spoiler alert! Don’t scroll down too far or you will see the answer! Let’s see the first one:
Solution: Number 2! In night photography you will get histograms with a lot of pick in the blacks area. But this is normal because night is dark and black is what we expect to find in the frame.
Solution: Number 1! We got a histogram with a lot of whites because the image is mostly white!
Solution: Number 4! Here the histogram shows picks in both blacks and whites and almost no middle tones because the photo has high contrast: white and black are the main colors.
Solution: Number 3! The beautiful Gaudi House and the most part of the photo is well exposed, so the histogram has a lot of middle tones. However, the sun-star makes the whites in the histogram quite high. Exactly what I wanted!
What do you think about histograms now? Still scary? I hope not! It takes a bit of practice to get used to them, but believe me, it is totally worth it! Grab your camera and tell me how it goes! Have a happy shooting!