Focal length is an optical measurement that determines how much of what you see in front of you is captured by your camera’s lens. A short focal length, such as 24mm, captures wide angle; a long focal length, such as 100mm, is telephoto. A “normal” focal length (50mm on a full-frame or film camera) roughly approximates how far away things appear to the naked eye. Focal length does not describe the physical size of the lens itself, but rather refers to its magnification.
