Optolong 2" H-Alpha, O-III, S-II Narrow Band Filter Set for Astrophotography

Optolong Narrow Band Filter Set

The Optolong SHO-3nm filter set includes 3nm SII, 3nm H-Alpha and 3nm OIII narrowband filters that are typically used with astronomical monochrome cameras and modified DSLR cameras.

Designed for nebula viewing, the 3nm SII Extra Narrow Band Filter passes a 3nm bandwidth centered on a 672nm wavelength.

The H-Alpha 3nm filter is a popular narrowband filter that passes a 3nm bandwidth at a wavelength of 656nm. Best narrowband H-alpha astrophotography filter choice for maximum contrast and fine nebula detail.

The 3nm OIII CCD Extra Narrow Band Filter has a 3nm bandwidth centered at a wavelength of 500nm, which corresponds to the OIII emission line. OIII emits at 495.9nm and 500.7nm and is a blue-green color filter. Many images of planetary nebulae and supernova remnants are taken with only H-alpha and OIIII filters. They show great structural detail but have natural colors and look like an RGB image.

The filters reliably block certain wavelengths of light, particularly those produced by artificial light, including high and low pressure sodium vapor and mercury vapor lamps, as well as unwanted natural light caused by the emission of neutral oxygen in our atmosphere (i.e. sky brightness).