How to prevent dust when changing lenses in outdoor shooting

It is difficult for CMOS to avoid dust, and a good camera's waterproof and dustproof function will be ideal. When changing the head, find the position of the lens bayonet to be changed in advance, then unscrew the hanging head and change it quickly to reduce the chance of dust entering.

Blow the mirror and CMOS clean with air every once in a while. If it still cannot be removed, you can use a professional jelly pen to clean it.