Composition and Cameras - Photographic Rendering with V-Ray for SketchUp - page 280

How focal length affects composition
The final important piece of information that we need to put into place here is again
both technical and creative and can potentially affect our final composition in quite a
drastic manner. This would be the choice of the focal or lens' length that we decide to
use for the rendering camera(s).
Note
Focal length can also be described in terms of a camera's Field Of View ( FOV ).
This setting describes the area of an environment that can be seen by our camera
and is expressed as an angle, measured of course using degrees.
The following simplified diagram gives us an idea of what happens whenever we ex-
tend the focal length on a real world camera lens:
Using a focal length of around 50 mm, the lens stays reasonably close to the body
of the camera and so produces a fairly broad FOV. As we dial in longer focal lengths
however, jumping all the way up to 2000 mm here, we physically move the lens away
from the body of the camera, creating a much narrower FOV that will of course dra-
matically alter the overall feel and composition of our shot(s).