Any of various instruments for measuring the intensity of light, or for comparing the intensities of light from different sources.

A spectroscope for use with the sun. Now historical.

An instrument designed to measure the relative intensity of light (usually transmitted or emitted by a substance under study) at different…

a device for measuring the intensity of light; esp. one that shows the correct exposure when taking a photograph (cf. exposure meter n. at exposure…

Used attributively to designate esp. a lamp devised by Hefner-Alteneck and formerly used as a photometric standard and the intensity of light…

A photometer, esp. one for measuring the illumination of surfaces (rather than the intensity of light sources).

An instrument for measuring the luminance (brightness) or illuminance (illumination) of a surface.

= luxmeter, n.

an instrument for measuring the intensity of light from a distant source.