A multiangle absorption photometer takes into account both transmitted and reflected light.
en.wikipedia.org It may also be measured with a photometer lowered into the water.
en.wikipedia.org The telescopes accommodate a wide variety of sensor systems, including imaging systems, conventional and contrast mode photometers, infrared radiometers, low light level video systems, and acquisition telescopes.
en.wikipedia.org The products he designed and manufactured included spectroscopes, telescopes, microscopes, barometers, photometers, cameras, ophthalmoscopes, and electrical equipment such as electric lamps.
en.wikipedia.org Two types of photometers are used: spectrophotometer and filter photometer.
en.wikipedia.org