Video mapping using Cinema 4d

[Contraband]

I have a video mapping project I'm working on. I have created the geometry I wish to project on in Cinema 4d, I now want to place cameras to emulate real life projectors, but I'm not sure how I should setup the cameras in Cinema to achieve this? Things like focal length, aperture width and field of view. Is there a formula to matching these with the projector so that the geometry will line up with the real life projection? Any help would be greatly appreciated!