This is maybe not a 100% on topic photography, but I couldn't find a better stackexchange site to post this on and maybe you guys can help me out.
I have a camera that takes pictures of a production process. The objects are all pretty close by, so nothing should be in hyperfocal distance. We have an autofocus that focuses on the object. Is it possible to calculate the distance from the camera by looking at the focus position. How precise would that be. It's a passive focus. I couldn't really find any material on this. Is this done at all? Does anybody know of some references for that problem? Is this a good or bad idea?