Samsung NX3000 User Manual (English) - Page 16

Concepts in Photography Aperture The aperture is one of the three factors that determine the exposure. The aperture housing contains thin, metal plates that open and close to let light through the aperture and into the camera. The size of the aperture is related to the amount of light: a larger aperture allows more light and a smaller aperture allows less light. Aperture sizes The size of the aperture is represented by a value known as an "F-number." The f-number represents the focal length divided by the diameter of the lens. For example, if a lens with a 50 mm focal length has an f-number of F2, the diameter of the aperture is 25 mm. (50 mm/25 mm = F2) The smaller the f-number, the greater the size of the aperture. The opening in the aperture is described as the Exposure Value (EV). Increasing the Exposure Value (+1 EV) means the amount of light doubles. Decreasing the Exposure Value (-1 EV) means the amount of light halves. You can also use the exposure compensation feature to fine-tune the amount of light by subdividing exposure values into 1/2, 1/3 EV, and so on. +1 EV -1 EV Minimum aperture Medium aperture Maximum aperture F1.4 F2 F2.8 F4 F5.6 F8 Exposure Value Steps Aperture opened slightly Aperture opened wide 15