According to the wikipaper http://wiki.mcneel.com/rhino/rhinolensing “when you assign a lens to a Rhino viewport using ViewportProperties, the resulting image you will see is what that lens would look like on a standard SLR 36mm x 24mm film gate camera.”
Knowing what the camera is calibrated for is really, really, really important for the film industry, where we are often asked to show exactly how much of a set one would see with a particular lens. Tables show that a 50mm lens on a 35mm film camera has a horizontal field of view of 39.6°. If the wikipaper is correct, then this is what the Rhino camera should show, yet when I ran a test the horizontal field of view was 50°. Alternatively a 50mm lens on a digital still camera has a horizontal field of view of 26.9°. But this doesn’t match either. Is there any explanation? Is the focal length designation on the Rhino camera arbitrary?