Optolong L-Ultimate Dual Band 3nm 2 Inch FilterOptolong L Ultimate Dual Band 3nm 2 Inch Filter Optolong L Ultimate Dual Band 3nm 2 Inch Filter 3nm is designed to drastically reduce the effect of light pollution. The 3nm bandwidth means it strongly isolates the nebulae's emissions into H Alpha (red) and OIII (green blue) from anything else. It blocks light pollution, maximizes the signal from nebulae, and darkens the sky background. It also blocks artificial light from mercury vapor lamps, high and

Exit Pupil (mm): 5 mm

and key features of the most popular celestial objects

Lowest Useful Magnification: 15x

Height Range:  24" - 41" (609mm - 1041mm)

Relative Brightness: 6

the product can also selectively filter light pollution and clutter signals through the emission lines of nebulae

Un-recharged shelf life of up to 10 years – 3 times better than lithium-ion and 10 times better than sealed lead-acid designs

or add automatic alignment functionality with StarSense AutoAlign

kindly chose Optolong other narrow-band filters

comparable to a Minus-Violet-Filter

and are characterised by their wide 58 degree field of view

With the DEC axis removed the mount only tracks in RA and you can easily take photos