Lumicon 82 mm Night Sky Hydrogen-Alpha (Ha) Filter
WARNING: DO NOT LOOK AT THE SUN THROUGH THE LUMICON Night-Sky H-Alpha Filter! Eye Damage could result from solar heat transmitted through this filter. The Lumicon Night-Sky Hydrogen Alpha Filter is designed to be used for Black and White Deep-Sky Photography (Not for solar or visual work). Transmission for this sharp-cut-off deep-sky photography filter is zero below 630 nm, 90% at Hydrogen-Alpha 657 nm, and 90-98% from 657 nm to the near infrared. Both filter surfaces have high-efficiency anti-reflection coatings for maximum performance. This Lumicon filter is designed with an 82 mm (3.23″) diameter OD thread cell to fit into camera lenses which take an 82 mm filter.
For Deep-Sky Photography: The Lumicon Night-Sky H-Alpha Filter is a powerful aid in overcoming light pollution, and will help you achieve strikingly improved results in telephoto lens B&W astrophotography. It is ideally matched to hypersensitized 2415 film, and will reduce light pollution 10-fold, making it ideal for photography of faint emission nebulae.
Filter Factor: Exposures may be increased 2-10 times with the Night-Sky H-Alpha Filter, depending on the faintness of the nebula. The Night-Sky H-Alpha Filter is not suitable for visual use. Hydrogen Alpha Pass filters are deep red filters blocking most of the spectrum with high transmission at the 656 nm hydrogen alpha line.