Factors affecting background blur

There are three main factors that affect background blur in photography.

1. Tools (camera lens, pixels, focal moment, aperture).

? 2. The influence of the theme. Ordinary people, flowers and animals can be blurred, but buildings and the like are not suitable for blurring, otherwise it will give people a very weak illusion.

? 3. Shooting skills, if there is confusion in the background, it needs to be blurred.

? If the background is clear, it can set off the theme and there is a good mirror, there is no need to blur it.