These two sites simulate lenses from Canon &/or Nikon showing the zoom and angle of view.
Nikon's site includes DX and FX lenses. Might help those trying to decide what they need.

http://imaging.nikon.com/products/im...ator/index.htm

http://www.usa.canon.com/app/html/EF...al_length.html

The zoom would be the same for other lenses too.