Photometric ( luminous) exposure


In photography, exposure is the amount of light per unit area (the image plane illuminance times the exposure time) reaching a photographic film, as determined by shutter speed, lens aperture and scene luminance. Photometric or luminous exposure is the accumulated physical quantity of visible light energy per area applied to a surface during a given exposure time.

Related formulas


H_νThe luminous exposure (lux*seconds)
E_νThe image-plane illuminance ( flux incident on a surface, per unit area) (lux)
tExposure time ( the length of time a camera's shutter is open when taking a photograph) (sec)