Many novice photographers face difficulties in using a histogram in photography, and some do not even consider it necessary to use it. What is a histogram, how does it work in the practice of professionals, and what gives a photograph? What is the best way to correct it - through the camera itself or subsequently when processing photos through the editor? What should a photographer know about exposure, contrast, chiaroscuro and other important meanings of photography? More about this in the article.
What is it?
So, a histogram - what is it? Many times, photographing a panorama or portrait, you transferred the pictures to a computer and wondered why with such bright full daylight they turned out to be too dark or, conversely, overexposed? It is quite difficult to control the brightness of the picture on the small monitor of the camera “by eye”, but you can adjust the optimal level. The histogram of the photo - this is the tool that shows the distribution of light and dark tones in the photo and allows for their uniform distribution.
There are several types of histograms on cameras - with a smooth gradient, with columns, with color and black and white horizontal. The most popular is in the form of a bell. But the principle of operation is the same for everyone - this is a graph that displays the brightness of the image from the darkest tones (left) to the lightest (right).
Before we understand how a histogram is read in photography, how to use values from 0 to 255, let's find out the opinion of professional photographers and determine for ourselves whether it is needed for a high-quality image, or you can do without it.
Histogram myths and misconceptions
There is much debate about whether or not to use this brightness graph. To figure this out, we’ll debunk some myths about how and when the histogram of the camera is used.
- Professional photographers determine the balance of chiaroscuro “by eye”, without relying on the processor of the camera.
- The data shown may be erroneous depending on the level of the camera.
- A photograph does not have to be perfectly measured by exposure; sometimes overexposure or blackout is part of the creative idea.
- The histogram of the photo, as a rule, is applied only when shooting in black and white.
- Professionals often trust the processing of RAW images in Adobe Photoshop, Adobe Lightroom, and some other proofreaders.
In this regard, opinions on the use of charts are divided into pros and cons.
Opinion “against”
Professionals with a trained eye rarely use this schedule, since it is time consuming and does not always lead to the desired result. For a beginner, it’s very difficult to read it straight away and understand which way to change the metering values, moreover, some erroneous values when taking pictures will be quite difficult to correct even with correction in the future.
Not all cameras, only professional ones, can give true true values of chiaroscuro, but they can be wrong. Anyway, in the future, the picture will have to be adjusted in the Photoshop and Lightroom editors, so working with a histogram will only take up precious time.
Opinion “for”
What are the benefits for those who know what a histogram is?
- Even if you are a professional photographer, a second glance cast at the chart will tell you how rich the image is in terms of tone transitions. Moreover, in many digital cameras you can display it directly on the display and look at it without breaking away from the creative process.
- If the shooting takes place not in a room (for example, in a well-lit studio), but in sunny weather in the park, it will be quite difficult for the photographer to objectively evaluate the image on the screen, since it can reflect and show colors more faded than they actually are . In night weather, on the contrary, the picture can turn out to be deceptively bright. And also on the screen it is difficult to perceive the accuracy of black and white and it is not easy to recognize which areas were “killed” by contrast. For this, a strict assessment tool is best - a histogram in a photograph.
- Sometimes, using a histogram, you can select a camera, it shows the breadth of the dynamic range, that is, how many colors the camera can capture when shooting. After all, it’s not always possible to take a picture when buying a camera, which will show all the colors from the generally accepted range of 0-255.
Summarizing all of the above, it is not always necessary to understand what a histogram in a photograph is, how to use it (practical application), but it is not superfluous, since there are cases when this knowledge cannot be dispensed with. Therefore, let's learn to read it and put it into practice.
How to read a histogram
So, what is the histogram in the camera and why is it needed, of course. Visually, it looks like a graph. On the horizontal axis, shades from black (dark) to midtones (medium in brightness shades) and white (light) are located from left to right. The vertical axis indicates the number of pixels of each hue in the image. As a result, we get several columns of different heights, the higher the column, the more this or that light. We will analyze in practice.
Underexposed frame
Underexposure means that the frame will turn out too dark. On the graph, the histogram of the camera is shifted to the left. What to do in this case? This means that there are a lot of dark tones, dark objects, black spots, and almost no light ones. If this is not the idea of the photo, and you are not just shooting a dark subject, go to the exposure settings and add 1-2 points up (value 1.3; 1.7).
Overexposed frame
Overexposure suggests the opposite: the frame turned out to be illuminated (a lot of light, glare of water, snow in the frame), or you are photographing a white (light) object. Again, if this is not provided for by the plot, go to the exposure and reduce its value to 0.7.
“Correct" frame
Now, knowing what a histogram is in the camera with incorrect exposure values, let's look at the correctly exposed frame. Visually, he looks like a boa constrictor eating a hat. This means that shadows and lights are present and correctly calibrated, but prevail in the midtone picture. Such a frame looks expressive, contrasting, clear and bright. Plus it will be easier to handle.
Opaque frame
The absence of dark and light areas, in other words, contrast, is as follows. The graph or bars are in the center and missing along the edges. This does not mean that the frame was exposed incorrectly, perhaps this is the author’s idea and contrasting elements should not be present in the photo. In any case, this ratio is easily corrected during subsequent processing.
Peaks on the chart
Two sharp peaks at the edges have a histogram. What it is? This option is often obtained when shooting contrasting objects - a land with dark grasses and a clear blue sky, for example. Such an exposure does not need to be adjusted, because it will not show other values.
High frame
Such kind of pictures are obtained when shooting in bright colors - white background, bright sky in sunny weather, clothes in bright colors. The histograms in such images strongly creep to the right, but this is not a mistake. The photo is light, airy and allows you to concentrate completely on the object of photography - an object or a person, without being distracted by unnecessary details.
In this case, it is better to leave the exposure at 1, since higher values will lead to overexposure. The brightness of the image can be increased already during processing.
Low key frame
There is a reverse situation when the chart goes completely to the left - for example, a still life is photographed on a black background. Here you should not be afraid of this bias, and adjust all details, brightness and contrast already during processing. Speaking of her.
Editing RAW format
Having found out what a histogram is in photography, how to use it when processing photos? Every photographer should know that a picture taken in RAW format saves the settings at which it was taken. Therefore, using the Photoshop program, the wizard has the ability to correct the mistakes made.
However, there are certain subtleties. An underexposed frame is easier to correct in the exposure plus, while a lighted one is almost impossible to fix. Therefore, situations with exposure should be avoided. To do this, check the exposure of the frame of each photo after work and use the light indicator in the camera settings.
How to work with a histogram in Lightroom
Why use a histogram on a computer if you have already adjusted the picture through the camera while shooting? It's simple, this is necessary in order to evaluate how the photo will look on an average computer. Indeed, on your mac-book it may be ideal, but on a friend’s laptop it’s completely dark, and on the print it’s completely different, not what you expect.
Using the Lightroom histogram, you can get all the complete information about shadows, contrast, brightness, etc.
So, the histogram in the photo. How to use when processing photos? In the program, it looks like a rainbow schedule. The right side, as well as in the camera, is responsible for the light, the left - for the shadow. The density of a particular color is shown by peaks, the lighter the photo, the higher the pixels on the right.
The most important thing to pay attention to when processing is the loss in light or shadows. If there are no values from the edge of one of the sides, it means that the image has lost some details. For example, dark hair merged into one or the blue sky turned into white.
How to fix it? In the diagram, you will find two triangles on the right and left. If you click on the left, blue in the photo highlights the loss in the shadows. If you click on the right, the losses will turn red.
To fix these losses, Lightroom has several tools that are located directly below the chart, these are:
- fill light;
- exposure;
- contrast;
- shadows;
- sharpness;
- color change and some others.
For example, contrast can help fix a chart where all the pixels are directed high in one direction, such a photo has a very low contrast. This is also indicated by the hump in the middle. But sharp peaks on both sides of the graph, on the contrary, speak of excessive contrast, which would not hurt to reduce.
How to work with a histogram in Photoshop
Professional photographers often use Lightroom to correct exposure and chiaroscuro, since this program has much more complete and convenient tools. But adjusting photos can be done using Photoshop. Here the histogram looks about the same. But with the help of "Photoshop" it is convenient to adjust the resolution and format of the image to ensure optimal color reproduction when printing images. It is also very convenient to apply filters, correct defects and change photo levels.
If you adjust and restore an old image, Adobe Photoshop will help you see the right colors, which should be in reality, where re-highlights or shadows abound.
How to open a histogram in this program? Go to the tab "Image", "Correction", "Levels". You will see a black and white graph in the form of mountains with a range from 0 (absolutely black) to 255 (white light). To change the exposure, scroll the gradient bar at the bottom, as well as the markers below the graph itself.
Learning in practice
The main rule that will help to understand what the histogram in the camera means is to practice more, take pictures with different exposure meters, under different lighting conditions and constantly analyze the resulting pictures.
Take several identical photos - one with an exposure of +1, the other at +0.3, the third at -0.7. See how their exposure differs. Try switching to a different shooting mode. How did the schedule change this time?
Check the same pictures with the help of graphic editors, see how they differ from the camera. Only practice can you better understand the understanding and necessity of using a histogram.
Instead of a conclusion
Of course, not just knowing what a histogram is, but also the ability to use it and configure it correctly will help to make really professional and high-quality pictures. But professionalism also consists of a lot of small knowledge about the intricacies of photography.
Naturally, every enthusiastic photographer should know the rules for building a successful composition, understand what manual settings are necessary for, such as shutter speed, aperture, focus and autofocus, dynamic range, calculating the depth of field and much more. He must understand what the correct histogram should look like when shooting in normal, low and high key, and when loss in chiaroscuro is considered normal. Where to use the overexposure to emphasize the composition, and where are they the lack of a picture? Where does the large amount of black in the frame make it difficult to concentrate on a key subject?
One thing is for sure, without knowing what a histogram is, it will be difficult for you to fix the settings to get the perfect shot. And whether to use this knowledge constantly or only in some cases is your choice. Have a nice photo shoot!