How to apply dynamic range in photography.

Sometimes you may find yourself in a well-lit situation, such as outdoors or a well-lit gym, and it will get dark at other times, so you need to use a flash to create your own light or open the shutter for a long time. However, if there is a lot of light and shadows, it is likely that photos will eventually be taken, and then it is very difficult to specify the photos to be taken. Fortunately, in these cases, there is a term that can greatly help you-it is dynamic range. Knowing what it means and how it affects your photography will greatly help you get the photos you are trying to create.

Make a scene (or situation) description beforehand.

When it comes to photography, dynamic range has two main applications. The first involves the scene you are shooting, and the second involves a highly technical technology, which helps to describe the properties of the camera image sensor.

Many times, photographers will try their best to take photos with good overall exposure, that is to say, the bright parts will not be too bright and the dark parts will not be too dark. In this sense, dynamic range refers to the total amount of light captured in a given scene. If there are many bright parts full of light and many black parts covered by shadows in the shot photos, the scene can be described as having a large dynamic range (high contrast). However, if the scene is illuminated too bright or too dark, it can be said that it has a low dynamic range (low contrast).

The dynamic range of this goose is very low, which means that its exposure is uniform, and no part is particularly bright or dark.

There is no right or wrong.

These two kinds of scenes are not necessarily good or bad, but it is important to know when to go out to take pictures and what the lighting conditions are, so as to make targeted plans. If you shoot in broad daylight, you may get a very bright image with many shadows, because the sun is strong and overhead. This is called a high dynamic range scene because it contains very bright and very dark elements. You need to know how to control the scene and camera when this happens to get the desired shot.

This photo of the goose was taken under conditions that led to a very high dynamic range. Some parts of the image are very bright, while others are covered by shadows.

Capture your vision

Dynamic range is very important when taking pictures. Knowing what you are shooting is very important for capturing the shot you want. If you paint with light, you need to know how light affects the final image.

For example, this is a portrait I took on a sunny afternoon. My theme is good, but the background behind it is bright. This led to my dissatisfied image. The audience's attention should be on her face, but the bright background is competing for attention.

The histogram will give you clues about the dynamic range.

By looking at the histogram of this image, I can reveal what I know only by observing the scene. Most image data is collected on the right and left side of the chart. This shows that the scene contains very bright and very dark parts, so the dynamic range is considered to be quite high.

A picture like this is not necessarily bad. Some photographers actually prefer scenes with really high dynamic range, because they will produce a sense of contrast and intensity, which is usually lacking in more uniform exposure in other situations. Personally, I don't like these types of pictures very much. In this case, you can easily fix them by turning them slightly in one direction and using one side of the building to create a more uniform exposure.

I can look at the histogram in Lightroom again and see that now the image data will not be separated at the two extremes, but gathered in one part more evenly. Alternatively, you can use the real-time viewing function on the camera to view the histogram in real time while shooting. If you see it looks like two peaks with a valley on both sides, it shows that there will be more contrast on the spot than you like.

HDR- high dynamic range

Recently, more and more photographers use a technique called HDR or high dynamic range processing. By allowing you to combine multiple exposures into one image and use only the parts you need, this is a way to kill two birds with one stone. Therefore, in a scene with a very bright part and a very dark part, you can take a few underexposed and overexposed photos, and then use the software on your mobile phone or computer to synthesize them, and finally get an evenly exposed image. One disadvantage of this is that the final image may be a little fake to our human eyes (if HDR technology is not done well).