George Scharoun

Hi thanks for your reply, and I see your point about the focal length of human vision not mattering. I need to clarify what I'm trying to do though - it's not to film an actual window, it's to film a landscape and then by projecting it in the gallery space we'd be creating a kind of virtual window. The objects in the image should appear life-size though, and that's where I believe the focal length comes into play. But based on your logic, we could just hold up a tape measure and say, 12' should just fill the frame vertically, when the camera is 15' away? Makes sense! Is it possible to figure this out before going on location though, so we book the right lenses?

Ok, I think this is kind of a cool unique problem to solve, but maybe someone will have a quick answer! Or they'll tell me I'm an idiot, which is very possible. I want to project a virtual window in an art gallery. The viewer will be positioned approximately 15' away from a 20' x 12' projection, and my hope is that by filming a static scene with the right focal length - adjusted for the viewing distance - that the effect will approximate the experience of looking out a big picture window. I'm not very good at geometry so I'm looking for help. I've only gotten as far as thinking that if the human eye's focal length is about 22mm (controversial I know), then this would be narrower because of your physical distance from the "window". But how much narrower? There must be a way to calculate it. Ok, I think I've over-explained at this point. Much appreciated if you could help me figure this out.