When most novice photographers start shooting portraits, they will take portraits with blurred background as a sign of getting started. In fact, it is very simple to blur the background, and background blur does have many advantages in portrait photography, so most portrait works we see are blurred background. So why on earth do most portraits blur the background?
I. Highlight the main body
As we all know, the subject of portrait photography is of course people. Yes, in portrait photography, people exist as the subject, and the most important person in portrait photography is to reflect the posture, movements, appearance and even emotions and emotions of the people in the photos. But in life, people are always in the surrounding environment, and the same is true when shooting. If you don't use the shallow depth of field effect to blur the environmental background, it will easily lead to disorder of the background, and sometimes the background will usurp the host's role. Of course, if you can choose a perfect background, you certainly don't need to blur it. The difficulty of environmental portrait photography is the choice of background. In environmental portrait photography, it is always necessary to ensure the consent of the characters and the environmental background. We call it "harmony between man and nature".
Second, the depth of performance
Another function of background blur in portrait photography is to express depth and increase the three-dimensional sense of the work. Why is it difficult for us to see the background blur in landscape photography? Because when shooting the scenery, the three scenes in the near, far and far have been able to express the three-dimensional sense and layering of the picture very clearly. In portrait photography, there is no division of near, far and far scenes, but at most, it is to add a foreground to the characters. At this time, we need to use the background blur effect to make the picture have a sense of depth, thus further realizing the three-dimensional sense and layering of the picture.
III. Cut the complexity and simplify it
Photography is the art of subtraction. As mentioned in New Photograph Textbook, what are the three principles that photography pursues? The theme is clear, the subject is prominent, and the picture is concise. The effect of background blur can satisfy the two principles. We have already talked about the principle of prominent subject at the first point, and another function of background blurring is to simplify the picture and blur the messy background to achieve the effect of concise picture, so that it is easier to shoot successful portrait photography works.
4. How to blur the background
The blur effect of the lens mainly depends on three elements: aperture value, lens focal length and shooting distance.
Let's briefly talk about how to blur the background here, just a few simple steps. First of all, we should understand that the degree of background blur is inversely proportional to the depth of field. The shallower the depth of field, the higher the degree of background blur, and the deeper the depth of field, the lower the degree of background blur.
Secondly, we need to know the relationship between the above three elements and depth of field. The smaller the aperture value, the shallower the depth of field; The greater the focal length, the shallower the depth of field; The shorter the shooting distance, the shallower the depth of field.
Having said that, you should also know that by opening a large aperture, using a long focal length and then shortening the shooting distance, you can get a shallow depth of field, that is, you can get a relatively high background blur effect.