Unihedron

Unihedron is a Canadian manufacturer best known for the Sky Quality Meter (SQM), a compact photometer that measures night sky brightness. Amateur astronomers, researchers and dark-sky advocates around the world use it. In just a few seconds it gives an objective reading in mag/arcsec², so you can compare observing sites with real numbers.

The range includes handheld meters for quick measurements in the field and connected models with USB, Ethernet or RS232 for continuous sky monitoring. Accessories such as a waterproof housing and a solar charger are also available.