Sky Quality Meter with Lens | Measure Night Sky Brightness | SQM-L

How good is your sky, really? Gather actionable quantitative data to track the sky's brightness and the evolution of seeing conditions over time or at different locations. Helps you decide when it's worth going out for an imaging session too. Join a global community of like minded astronomers in the process.

An affordable meter for measuring sky brightness for astronomers, the "Sky Quality Meter" measures the brightness of the night sky in magnitudes per square arcsecond. Designed by Dr. Doug Welch and Anthony Tekatch, the Unihedron Sky Quality Meter offers unprecedented sensitivity in a handheld meter.

Uses:

● Find out how good the night or site REALLY is.
● Compare the sky brightness at different sites quantitatively.
● Document the evolution of light pollution in your area.
● Monitor sky brightness through the night, night-to-night, and year-to-year.
● Join the "Loss of the night' program which is a worldwide science project that measures light pollution. Upload your results on a map together with thousands of users making their own measurements.
● Determine which nights show the greatest promise for finding the faintest deep sky objects!
● Calibrate the effect of sky brightness on qualitative measures such as the Bortle Scale.
● Investigate how sky brightness correlates with the solar cycle and month-to-month sunspot activity.
● Help provide local ground truth for future sky brightness prediction with the Clear Sky Clock

Features:

● Audible signal while measurement is in progress.
● Sky brightness displayed in visual magnitudes per square arcsecond.
● Infrared blocking filter restricts measurement to visual bandpass.
● Temperature in both Celsius and Fahrenheit as well as model number and serial number can be displayed with different button press sequence.
● Precision readings at even the darkest sites.
● Power-saving features designed in for maximum battery life.
● Reverse battery protection.

Specifications:

● The Half Width Half Maximum (HWHM) of the angular sensitivity is ~10°. The Full Width Half Maximum (FWHM) is then ~20°. The sensitivity to a point source ~19° off-axis is a factor of 10 lower than on-axis. A point source ~20° and ~40° off-axis would register 3.0 and 5.0 magnitudes fainter, respectively. (See photo 2)
● Operates from 9V battery (included).
● Size 3.6 x 2.6 x 1.1 in.
● Maximum light sampling time: 80 seconds.
● Specifications are subject to change without notice.

>>> Download the instruction manual here <<<