The cookie settings on this website are adjusted to allow all cookies so that you have the very best experience. If you continue without changing your cookie settings, we'll assume that you are happy to receive all cookies on our website. However, if you would like to, you can change your settings at any time using the Change cookie settings link in the Special menu.        
Home > Sky Quality Meter - L with Lens

Sky Quality Meter - L with Lens

Sky Quality Meter - L with Lens
Price: £108.00
Incl. VAT 20% ( £18.00 )
Product code: SQM-L
Add to wish list

An affordable meter for measuring sky brightness for astronomers. The "Sky Quality Meter - L" measures the brightness of the night sky in magnitudes per square arcsecond. Unprecedented sensitivity in a handheld meter. Used by professional observatories and universities to measure light pollution and transparency. Contribute your readings to the Sky Quality Database to help build up a record of the best observing sites in the UK and Europe as well as world wide. This could also help provide evidence of increasing light pollution in your area.

Designed by Dr. Doug Welch and Anthony Tekatch

  • 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.
  • Set planetarium dome illumination to mimic the skies people are likely to experience elsewhere in the city.
  • Monitor sky brightness through the night, night-to-night, and year-to-year.
  • Determine which nights show the greatest promise for finding the 'faintest fuzzies'!
  • 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.
  • CCD users can make a correlation between the SQM reading and when the background reaches some ADC level.


  • 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.



  • 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.
  • 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.

Unihedron supports the goals of the International Dark-Sky Association .

Details: Useful links:

Customer feedback

Customer Reviews

There have been no reviews for this product.

Send to friend

: *
: *
: *
Type the characters you see in the picture:

Gift certificates