What is the "depth of field effect"?

Depth of field effect refers to the range that can still be clearly seen before and after when the focus is on a certain point. It can decide whether to blur the background to highlight the subject or shoot a clear background.

In photographic works, it is often seen that the background is blurred when shooting flowers, insects and so on (called small depth of field). But when taking commemorative photos or group photos, landscape photos, etc. The background is usually as clear as the subject (called large depth of field)

Extended data:

There are three decisive factors of depth of field: lens focal length, object distance and aperture size.

The shorter the focal length of the lens, the wider the range of depth of field, the smaller the aperture and the greater the depth of field. A super wide-angle lens has a great depth of field at almost all apertures. Even with the smallest aperture, the depth of field of telephoto lens is very limited. Some single-lens reflex cameras have a depth of field prediction button, so you can predict the depth of field before pressing the shutter.

Baidu encyclopedia-aperture

Baidu Encyclopedia-Depth of Field Effect