What is a Densitometer?

A Densitometer is a color measuring device which detects the brightness of light in the visible spectrum as a way to determine the concentration of opaque coloring material in an emulsio, or the thickness of an opaque material on a substrate. The quantity of the colorant often correlates closely with the inverse log of the brightness of the detected light. That mathematical result is often as the “density” of the colorant.  The measuring instrument can include filters that limit the response to the presence of only a few colorants.