The original Lumicon 2" Ultra High Contrast filter is unbeatable for revealing nebulosity. This is achieved by passing three nebula emission lines-the two doubly ionized oxygen lines (496 and 501nm) and the H-beta line (486nm)-while blocking light-pollution and Sky Glow. The result is superb views of the Orion, Lagoon, Swan and other extended nebulae.
The 1.25" filters employ industry-standard 1.125" x 42 tpi threads (except for Questar/Brandon, which use a thread pattern unique to Questar). The 48 mm filters employ industry-standard 48 x 0.75 mm threading, which thread into 2" eyepieces. All larger filters use the given size with 0.75 mm pitch (e.g. a 72 mm Minus Violet filter has 72 x 0.75 mm threads).
Note! Recommended for telescopes 8" and larger in aperture
