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Unihedron Sky Quality Meter with Lens (SQM-L)

SKU : UH-SQM-L

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  • An affordable meter for measuring sky brightness!
  • Unprecedented sensitivity in a handheld meter!
  • Measures the brightness of the night sky in magnitudes per square arcsecond.
  • Designed by Dr. Doug Welch and Anthony Tekatch.

 

Product Details

  • The Sky Quality Meter-L measures how clear the night or site is. Compare the sky brightness at different sites with measured results! If you're a CCD use, you can make a correlation between the Unihedron SQM-L reading and when the background reaches some ADC level.

    How to Use the Sky Quality Meter-L

    • Keep track of the evolution of light pollution in your area.
    • Set planetarium dome illumination to mimic the skies you are likely to experience elsewhere in the city.
    • Monitor sky brightness through the night, night-to-night, and year-to-year.
    • Determine which nights are the greatest for finding the faintest of lights.
    • 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 of the Sky Quality Meter-L

    • Receive audible signals while measurement is in progress.
    • The sky brightness measure is displayed in visual magnitudes per square arcsecond.
    • Its infrared blocking filter restricts measurement to its visual bandpass.
    • Temperature is measured in both Celsius and Fahrenheit.
    • The model number and serial number can be displayed with different button press sequences.
    • Receive precision readings at even the darkest sites.
    • Its power-saving features provide maximum battery life.
    • Reverse battery protection.

      Full List of Specifications for the Sky Quality Meter-L

      • The Half-Width Half Maximum (HWHM) of the angular sensitivity is ~10 degrees.
      • The Full-Width Half Maximum (FWHM) is then ~20 degrees.
      • The sensitivity to a point source ~19 degrees off-axis is a factor of 10 lower than on-axis. A point source ~20 degrees and ~40 degrees 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 inches
      • Maximum light sampling time: 80 seconds
      • Specifications are subject to change without notice.

      OPT Product Number: UH-SQM-L 

       

    • specifications

      Warranty1 Year Warranty
    • included items

      • An affordable meter for measuring sky brightness!
      • Unprecedented sensitivity in a handheld meter!
      • Measures the brightness of the night sky in magnitudes per square arcsecond.
      • Designed by Dr. Doug Welch and Anthony Tekatch.

       

    Product Reviews

    Customer Reviews
    4.9 Based on 12 Reviews
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    Filter Reviews:
    PH
    01/21/2021
    Phillip H.
    United States United States
    Sky Quality Meter

    Picked this up as the developer of the iPhone app has quit development and I wanted accurate readings to help plan my Astrophotography sessions. Works well and is easy to use.

    RW
    12/12/2020
    Robert W.
    United States United States
    About as simple as it gets Sky Brightness

    Very nice light instrument that is easy to use and accurate. Also light and small.

    JC
    12/09/2020
    john c.
    United States United States
    hot item

    works good. now i know what the true bortle reading of my area is.sharpcap has a calculator to convert your reading to a bortle rating.i give it 5 stars. john c

    OPT Telescopes Unihedron Sky Quality Meter with Lens (SQM-L) ReviewOPT Telescopes Unihedron Sky Quality Meter with Lens (SQM-L) Review
    A
    05/15/2020
    Anonymous
    United States United States
    Excellent product...

    I always wondered how dark the sky was where I live. The maps always said that I was living in a rural sky but now with this device, I was able to get a true reading on the Bortle scale of usually over 21.60...much darker than I realized. By measuring the sky before I pull out my telescope, I can get a very good preview of the night viewing. The sky quality meter has proven to be worth ever penny.

    LW
    07/16/2019
    Lei W.
    United States United States
    Works as expected

    easy to use, values fairly consistent.

    HP
    03/11/2019
    Helen P.
    United States
    Unihedron Sky Quality Meter with Lens (SQM-L)

    Excellent: I would definitely buy from you again.