ZWO 36mm 7nm Narrowband H-Alpha/OIII/S-II Filter Set

The ZWO 36mm Narrowband H-Alpha, SII, and OIII Filter Set is designed to enhance astrophotography and observation of emission nebulae. Each filter isolates a specific wavelength H-Alpha (656nm), SII (672nm), and OIII (500nm) to produce high-contrast, detailed images. By effectively suppressing light pollution from artificial sources and reducing unwanted atmospheric oxygen emissions, these filters help reveal faint nebular structures with greater clarity.

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