A photometer is a device for measuring photometric quantities. The measured parameter is mainly illuminance, and other photometric quantities are derived from the illuminance. Photometers are adapted to the spectral brightness sensitivity of the eye.
Goniophotometers are special measuring devices for determining the luminous intensity distribution of luminaires. Either the measuring head moves around the luminaire or the luminous flux of the luminaire is directed, via a movable mirror, onto the fixed measuring head.