Neutral extinction range 85% - 30%.
Planoptically polished 31.7mm filter
An Ideal filter for sun and Moon observation and contrast enhancement in planetary observations. To screw into any 1¼" - or 2" eyepieces - for example the Baader Herschel prism (#2956500P or 2956500V) Rotate the filter in its cell and adjustments can be made to the variable brightness of the image being viewed to suit current magnification.
NOTE: for solar observation with a Herschel prism, you do not need a double polarizing filter. The reflected image of the sun from the Herschel prism is already partially polarized. If necessary please order the simple polarizing filter for further light attenuation. When used with an Astro Solar film, however, you need a double pole filter to continuously further mitigate the unpolarized sunlight.