Apart from the quantum efficiency it depends on the incident photon flux and the exposure time, which is equivalent to the exposure and the sensor area; since the exposure is the integration time multiplied with the image plane illuminance, and illuminance is the luminous flux per unit area.
32.
Similarly, the adjective " bright " can refer to a light source which delivers a high luminous flux ( measured in lumens ), or to a light source which concentrates the luminous flux it has into a very narrow beam ( candelas ), or to a light source that is seen against a dark background.
33.
Similarly, the adjective " bright " can refer to a light source which delivers a high luminous flux ( measured in lumens ), or to a light source which concentrates the luminous flux it has into a very narrow beam ( candelas ), or to a light source that is seen against a dark background.
34.
Daylight factor is the ratio of the illuminance at a point on a plane, generally the horizontal work plane, produced by the luminous flux received directly or indirectly at that point from a sky whose luminance distribution is known, to the illuminance on a horizontal plane produced by an unobstructed hemisphere of this same sky ."
35.
But the basic results of recent research are unambiguous : assuming equal luminous flux ( that is, equal amounts of visible light ), and matched optical characteristics of the fixtures ( particularly the amount of light allowed to radiate directly upward ), white sources rich in shorter ( blue and green ) wavelengths produce dramatically greater sky glow than sources with little blue and green.