by Lumicon
Date first available at Amazon.com: July 13, 2011
1 used & new from $109.95
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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.Lumicon Night-Sky Hydrogen Alpha Filter, for Black and and White Deep-Sky Photography (Not for solar or visual work). Transmission for this sharp-cut-off deep-sky photography filter is zero below 630nm, 90% at Hydrogen-Alpha 657nm, and 90-98% from 657nm to the near infrared. Both filter surfaces have high-efficiency anti-reflection coatings for maximum performance.
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 and and 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 656nm hydrogen alpha line.