photometry
Scientific term for measuring light intensity, brightness, or luminous flux. Used in physics, astronomy, and photography.
In astronomy, the brightness of stars is examined through photometry.
This camera has excellent photometry capabilities.
photometer
spectrophotometry
Compound of 測 (そく, 'measure') and 光 (こう, 'light'). The reading そっこう results from the assimilation of そく + こう.