What should I do in real time when shooting a micro-film with a SLR?

It is better to shoot micro-movies manually with SLR. Even now, cameras such as 80D are called seamless follow-up, but they are often unsatisfactory to use.

I suggest you add two devices:

The monitor, even the smallest 7-inch monitor, can see the focus well when using. After all, the SLR screen is only 3.2 inches, and there are about 400 monitors to meet your focus requirements.

Follow-up focus, follow-up focus changes the angle and accuracy of the hand when focusing. Follow-up focus is limited by AB, which is especially convenient when shooting shifted lenses. The price is also around several hundred yuan, less than 1000 yuan with rabbit cage, shoulder support and sunshade bucket.