Optolong Variable Polarizer Filter 2 Inch

Optolong Variable Polarizer Filter 1.25

A variable polarizing Moon filter consists of two single polarizing filters coupled together. One of these has threads to attach to the bottom of eyepieces or other threaded adapter barrels, and the second filter can freely rotate over 360-degrees, thus allowing you to control the brightness of the image over a wide range.

You simply rotate the lower filter until the image brightness is pleasing and comfortable for you, given your telescope aperture and the phase of the Moon. While primarily meant for use while observing the Moon, this filter can also help with observations of other bright objects like Venus and Jupiter. 

Please note, however, that unlike some other similar filters on the market, the two Optolong filter components of this item cannot be separated.

Variable Polarizer Specification

Substrate: Optical Glass Schott B260
Thickness: 2.0mm
Surface quality: 60/40
Transmitted Wavefront RMS: λ/4
Parallelism: 30s

WARNING: The filters of Optolong are not designed for sun observation. DO NOT LOOK AT THE SUN WITH OPTOLONG FILTER. You would be BLIND if you fail to observe the warning.