Portrait later series tutorial 1: What should I do later?

For a long time, there has been a great controversy about the later period. Some photographers like to work hard in the later stage, and some like to think that the later stage is keyboard photography, but it is not a real photography technology. In fact, with the rapid development of modern digital cameras and the powerful functions of Photoshop, why should we worry about whether the early stage is important or the later stage is important?

The later stage is the icing on the cake. I don't think it is necessary to polish the photos later to achieve better results. It is an interesting exploration process. But at the same time, we can't ignore the early shooting because of the powerful function of the later stage. Photography should be completed in the early and late stages with a perfect attitude.

So starting from today, we will explain some basic knowledge about portrait photography later, and share some examples according to the situation records later.

What are we going to do in the post-portrait era? Generally speaking, it can be divided into three parts: the adjustment of black, white and gray, the touch-up of the main body of the character, and the color matching of the photo. The adjustment of black, white and gray involves the treatment of exposure, contrast, highlights and shadows. The touch-up of characters includes peeling, liquefaction and makeup, and the color matching includes overall color matching and local color matching, which makes the colors of photos look more comfortable and beautiful.

For the above-mentioned content to be adjusted, PS will use tools or filters such as mask, camera Raw, curve, liquefaction, imitation stamp and optional color. It doesn't matter if you don't use these functions now, but we will demonstrate them in detail when we talk about specific functions later. But before using these functions skillfully for post-operation, we should first understand some very important basic knowledge.

What we want to know in today's lecture is, what is a histogram?

In the early stage of learning photography, histogram control must be in place. The histogram shows the number of pixels with different brightness. If overexposed and underexposed, pixel overflow will appear on the histogram.

First forget the color, and then understand black, white and gray. The horizontal axis of the histogram represents brightness. From left to right, it is divided into 256 levels of brightness, and the greater the abscissa value, the higher the brightness. The leftmost 0 represents pure black, and the rightmost 255 represents pure white. A photo can be divided into five brightness parts-black, shadow, midtone, highlight and white.

RGB histogram indicates how many pixels are contained in different gray levels. Let's take a look at the following photo:

You can look at the histogram in the upper right corner. The pixels are concentrated in the right area, and the rightmost pixel is "cut off", indicating that there is overexposure, and the details of the overexposure area are lost, leaving only white pixels to fill the content. Obviously, the sunlight and other parts in this picture are the reasons for the insufficient details of overexposure.

As can be seen from the photo and histogram, this picture is underexposed, and the pixels are concentrated in the left part of the histogram, and the leftmost pixels are "cut off". It can be seen that the parts that are filled with black pixels and lose details due to insufficient exposure correspond to elements such as trees in the photo.

For a photo with accurate exposure, its pixels are concentrated in the middle of the histogram and gradually decrease to both sides instead of being suddenly truncated, as shown in the following figure.

Histograms can be seen in cameras, camera raw data and curve tools. Sometimes because of the need of style, photos can be underexposed or overexposed. However, in general, it is necessary to ensure the normal exposure of photos in the early stage for later processing, otherwise some details of overexposure or underexposure are missing and cannot be processed in the later stage. Because PS is a graphic processing software based on pixel processing, in this lecture, we should establish an idea that pre-shooting ensures correct exposure.

Next let's talk about how to adjust the exposure in PS.