At that distance, this is the amount of view you get through your scope from right to left. FOV decreases as magnification is increased. FOV increases as magnification is reduced. A common 3x variable scope, for example, may have a FOV of a little over 30 feet at 100 yards, and a FOV of roughly 14 feet at 9x. These statistics will not change if the objective lens diameter is increased. The architecture of the eyepiece has a direct impact on the field of view.