There are two reasons:
1. Avoid the noise of the projector.
It is often strict, especially high -end models, because of the demand for heat dissipation,
There will be wind noise, this noise is in a quiet audio and video room,
Very obvious, it will seriously affect the effect of watching the movie.
2. Avoid discomfort from large machine calories to watching movie, because projection
The heat of the machine is large, and the heat dissipation is fast. If it is a large machine, such as screening
He will have a lot of calories such as machines, which will make the nearby view
The filmmaker is very uncomfortable, so that it completely violates our high -end theater
The original intention.