ZWO 2" 7nm Narrowband H-Alpha Filter

The ZWO H-Alpha filter has a bandpass of 7nm and passes light at 656nm wavelength, the light transmission rate comes up to 80%. Best choice of narrowband H-alpha astrophotography filter for high-contrast imaging and revealing rich details of the nebula even in areas with strong light pollution, just prepare to experience the infinite fun with it!

Narrowband filter does not eliminate the effects of light pollution or increase the object's brightness. In many cases, they increase the contrast between the nebula and the night sky, not brightening the nebula.

It can reduce the transmission of certain wavelengths of light, specifically, those produced by artificial light including mercury vapor, and both high and low-pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow).