Baader Green 500nm Bandpass Filter - Round Mounted - FCFG- Size:2" A modern Barlow lens will

A modern Barlow lens will not degrade your telescope''s optics

5mm of eye relief

The Sky Mentor 5X Five Element Barlow Lens - 2" will come in handy for extending the effective focal length of short-tube telescopes

Excellent 53 degree field of view

Baader Green 500nm Bandpass Filter - Round Mounted - FCFG- Size:2" A modern Barlow lens willAbout the Baader Green 500nm Bandpass Filter Round Mounted Baader Planetarium astronomy filters by far supersede the mediocre quality of common "flame polished" color filters. A fine optical polish and 2 mm thick glass allows the Baader Green Filter to be inserted anywhere into the optical path without introducing astigmatism or other defects. For instance, they can be used in front of a binocular viewer without degrading the image in any way.