Zoom lens A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a prime lens.
Cheat sheet Exposure Aperture Aperture Shutter Shutter ISO ISO Try to keep your light meter at 0 Shallow depth of field Brighter Deep depth of field Darker Longer exposure Brighter Shorter exposure Darker Low, higher quality (smooth) Day High, lower quality (noisy) Night