I own some of the Nikon lenses (24mm f2.8, 28mm f.28, 50mm f2.8, 55mm f1.4 macro, 85mm f1.4, 135mm f2.8, and 180mm f2.8). For the most part, I understand the usage of a wide angle, standard, and telephoto lens; however, my question is more towards visual effects then the purpose a wide angle, standard, or telephoto lens. For example, I can use a 180mm lens and filmed at a farther distance or use a 50mm lens and filmed at a closer distance. Now, I believed it all has to do with focus, DOF, compression of space and so on, so I guess my question is, in what situation (such as in what kind of scene) would I use what lens? Another example is zoom lens such as this demo. When do I use a zoom lens versus a prime lens?