I'll post this question here because it probably happens more often than not in sports. As I watch the baseball playoffs I see the photographers behind home plate shooting through the black mesh netting. Obviously they are able to do it or they wouldn't be there. My question is what are the physics behind the ability to focus past the net? Or should I say what are the limits at which that can be done? As in the thickness of the net, color, minimum aperture lens, distance to subject and focal length, etc...?