How does a digital SLR camera blur the background and highlight the subject?

Hello! \x0d\ to "take a picture with clear subject and blurred background" is the shooting technique of "blurred background". \x0d\ Fuzzy background involves many factors. The main factors are: \ x0d \ x0d \ focal length-the longer the focal length, the smaller the depth of field and the more blurred the background (and foreground). \ x0d \ aperture- The larger the aperture, the smaller the depth of field and the more blurred the background (and foreground). \x0d\ Object distance-The closer the object distance is, the smaller the depth of field is, and the more blurred the background (and foreground) is. \x0d\\x0d\ Based on the above factors, if shooting conditions permit, you should: 1, and use a large aperture (small aperture value) as much as possible; 2. Longest focal length (large focal length value); 3, the lens as close as possible to the subject. \x0d\ In addition, the background should be arranged as far away from the subject as possible, so that you can take photos with blurred background and clear subject as much as possible with limited equipment. \x0d\\x0d\ In addition, post-production can be carried out by image processing software such as Photoshop, and the desired effect can be obtained, but this kind of production requires proficiency in image processing software. However, the post-production system has an unnatural effect because there is no gradual change of depth of field.