The whole body of photography is clear, but why is the background blurred?

In fact, the problem of blurred background should include two factors. The combination of these two factors is the depth of field, which is the clear range in the depth of the picture. For example, in this case, people are basically within the depth of field, which is very clear, and then the background is blurred outside the depth of field.

One of these two factors is the aperture. The larger the aperture, the smaller the depth of field, and the more difficult it is to control. For example, if the object is standing, he may be fully aware. Once he is sitting and lying upright, he may not be clear all over.

The second is the focal length. The wide-angle lens has a large depth of field, and the scene in the picture has a sense of space. The telephoto lens has a small depth of field and the scene in the picture is compressed.

Of course, another reason is that the quality of the lens itself is related to the price.

So you choose the appropriate aperture and focal length, and then adjust the focus ring according to the distance of the subject, and you can get the effect of clear background and blurred characters. Of course, it's still the same problem. The blur effect depends on the lens.

I hope my answer can help you.