I have a scene I want to render where a small object moves across the camera's field of view. The rest of the scene is just a black void containing absolutely nothing (see image below). I need to render this as an image sequence.
This object is basically a mirror reflecting a somewhat complex scene, so I want to render it with a very high resolution (14mpx or more). And enough samples to get a good quality on the reflections.
The problem is that if i rise the number of samples, and because of the high resolution, it takes ages for each frame to render, while most of the time is just spent rendering a black region. The camera must stay static during the whole sequence.
Is it possible to configure blender to use a high number of samples around the object, and a very low value on the empty region? (I want to make the whole process faster)
I used the option border in the render menu, as described in this answer