This H-alpha Photographic narrowband filter has a 7nm bandwidth of light centered on a wavelength of 656nm through. Which adds in reducing 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. Also including the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. skyglow). Best choice of narrowband H-alpha astrophotography filter for highest contrast and revealing subtle nebula details.

• Adds in reducing the transmission of certain wavelengths of light
• Best choice of narrowband H-alpha astrophotography filter for highest contrast and revealing subtle nebula details

• Pegasus Astro H-alpha Photographic Filter - 2" Mounted