The FOV is equivalent to changing the focal length, just like switching lenses on a camera. But it is measured in degrees rather than millimetres. Pop into Bryce and load an appropriate scene. Pick your object and adjust this setting quite a bit to the right. Then move your camera viewpoint so that your object fills the same space it originally did. The wide-angle effect should become painfully obvious. 1 degree is an extreme telephoto while 180 degrees will wrap half of Bryce world in front of you. Without meaning to sound critical, there comes a time when you just have to try it and see for discussion has its limits. Actually, I should take my own advice :-)