Why should we blur the background in portrait photography?

It can be found in many portrait photography works that most of the works will blur the background. This does not mean that the background must be blurred when shooting portrait photography works, but the background blur becomes It has become a trend and major trend in portrait photography now, but in some special photography categories, such as environmental portrait photography, background blur basically does not appear.

When most novice photographers first start taking portraits, they will take portrait photos with a blurred background as a sign of entry. In fact, it is very simple to achieve a blurred background, and the background Blur does have many advantages in portrait photography, so most of the portrait works we see have background blur. So why do most portrait photography blur the background?

1. Highlight the subject

As we all know, the subject of portrait photography is of course people. Yes, in portrait photography, people exist as the main subject. The most important person in portrait photography is to reflect the person's posture, movements, appearance and even emotions and moods in the photo. But in life, people are always in the surrounding environment, and the same is true when shooting. If you do not use the shallow depth of field effect to blur the environmental background, it will easily cause the background to be messy, and sometimes the background will take over the focus. Of course, if you can choose a perfect background, you certainly don’t need to blur it. The more difficult part of environmental portrait photography than ordinary portrait photography is the selection of the background. In environmental portrait photography, you must always ensure that the characters and If the environment and background agree, we call it "harmony between man and nature."

2. Expressing depth

Another function of background blur in portrait photography is to express depth and increase the three-dimensional sense of space in the work. Why is it so difficult to see background blur in landscape photography? Because when shooting landscapes, the near, middle and far scenes can already express the spatial three-dimensionality and layering of the picture very clearly. In portrait photography, there is no division between near, middle and far scenes. At most, a foreground is added to the character. At this time, we need to use the background blur effect to create a sense of depth in the picture, thereby further realizing the three-dimensional sense and layering of the picture.

3. Cut out the complex and make it simple

Photography is the art of subtraction. As mentioned in "New Photography Textbook", what are the three principles pursued by photography? The theme is clear, the subject is prominent, and the picture is concise. The effect of background blur can satisfy the two principles here. We have already talked about the principle of highlighting the subject in the first point, and another function of background blur is to streamline the picture and blur the messy background to achieve a concise effect. This makes it easier to shoot successful portrait photography. .

4. How to achieve background blur

The blurring effect of the lens mainly depends on three factors: aperture value, lens focal length, and shooting distance.

Here we will briefly talk about the method of blurring the background. It only takes a few simple steps. First of all, we need to understand that the degree of background blur and depth of field are inversely proportional. The shallower the depth of field, the higher the degree of background blur. 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 larger the focal length, the shallower the depth of field; the shorter the shooting distance, the shallower the depth of field.

Having said this, everyone should also know that by opening a large aperture, using a long focal length, and then shortening the shooting distance, you can obtain a shallow depth of field, which means a relatively high background blur effect.