luminous intensity; light intensity
Technical term used in physics and lighting; also used more generally for the brightness of a light source.
The luminous intensity of this light bulb is 800 lumens.
光度を測定する装置を光度計という。
A device that measures light intensity is called a photometer.
photometer
absorbance; optical density
photographic sensitivity; film speed
light curve
Compound of 光 (light) and 度 (degree, measure). The reading こうど is the on'yomi of both characters.