"Maybe I'm not clear about what you are saying, but surely if 3d software was to add format of the film or sensor size it would limit the render resolution? Maybe film or sensor size could be added as an option, but one of the big advantages of digital software is that there is not a restrictive limit to render size...I would put that as a big plus." you're not understanding either focal length or perspective transforms work. Most GP 3D apps - Maya, Xsi, Houdini - don't work in the quite limited way Vue works and with good reason; focal length is meaningless unless you take into consideration the format you're working with. And it's not a plus at all, it's a pain because it's misleading and just plain wrong. http://en.wikipedia.org/wiki/Angle_of_view : calculation of FOV from Focal length. http://en.wikipedia.org/wiki/Perspective_transform : detailed description of how world to screen transformations work.