About the Lumicon Hydrogen-Beta (H-Beta) Filter - 2"...
The Lumicon H-Beta Filter isolates only the Hydrogen-beta line of the spectrum (486.5nm) while blocking, completely, the rest of the overall spectrum of light. The result is extreme contrast between the black background of space and the delicately attenuated H-beta light needed to view a few select, extremely faint objects such as the Horsehead, Cocoon and California Nebulae. In many cases the Lumicon H-Beta Filter is the ONLY way to view those objects. A steady, transparent sky, 8" or larger aperture (in most cases) and a maximum-efficiency exit pupil (7mm), combined with the Lumicon H-Beta Filter, all make an unbeatable combination for viewing those "notch in the belt" objects.
Lumicon measures every Lumicon H-Beta Filter individually on a Perkin-Elmer Double-Beam spectrophotometer, inscribing on the filter its percentage of transmission for the primary H-beta Line. With this filter, all nebulae may be checked for H-beta emissions, with reference to views given by your other Lumicon filters.
Not intended for photography.
Lumicon Hydrogen-Beta (H-Beta) Filter - 2" Features...
- Exclusively designed dielectric coatings consist of over 30 alternating layers of several different
- Each layer is about a wavelength of light thick and has a thickness accurate to 2 - 3
- Consists of two elements, sandwiched coatings, and anti-reflection coatings on all surfaces to
- Tested individually on a Perkin-Elmer Double-Beam spectrophotometer, inscribing on the filter its percentage of transmission for the primary H-beta Line.
- Extremely narrow bandpass filter isolating the hydrogen-beta line alone (486nm).
Lumicon Hydrogen-Beta (H-Beta) Filter - 2" Specifications...
Filter Type: Hydrogen Beta
Filter Size: 2"
Presentation: Round, threaded cell
Optimum Exit Pupil (Light Polluted Skies): 3-7mm
Optimum Exit Pupil (Dark Skies): 4-7mmLumicon Product Number: LF3060