Alpine Astronomical Baader UHC-L Ultra-L-Booster Nebula Filter (31mm, Unmounted)

Designed to filter out light pollution, including LED light, the Alpine Astronomical Baader UHC-L Ultra-L-Booster Nebula Filter produces bright, high-contrast, accurate-color images and views of nebulae and comet tails. Its two passbands admit H-alpha, H-beta, and O-III lines while rejecting stray light from LED lamps, traditional streetlights, headlights, and natural sky glow. The filter features Reflex-Blocker coatings and Life-Coat sealed edges for halo-free, CMOS-optimized performance, and is bright enough to use with slow or small-aperture telescopes as well as large, fast instruments.

• Ultra high contrast L filter blocks city lights and increases contrast of nebula and comets (C2 lines)
• Can be used as LED-optimized luminance filter for RGB-imaging with skyglow suppression
• Blue transmission optimized to block blueish skyglow caused by LED headlights and streetlights
• Creates a much brighter image than a conventional nebula filter
• Ideal for deep-sky observers and the perfect visual complement to narrowband O-III filters
• Reflex-Blocker hard coated and planeoptically polished with sealed coating edges (Life-Coat)
• Blackened edges all around, with filter-lead-side-indicator in the form of a telescope-sided black outer rim