Lumicon 2 Inch SCT Rear Cell Hydrogen-Beta Filter is also known as the Horsehead Nebula filter. This filter isolates only the hydrogen-beta line of the spectrum (486nm) in a narrow pass-band just 9nm wide, providing maximum contrast. The filter-cell threads onto a Schmidt-Cassegrain Telescope rear-cell, and presents male SCT threads for accessory attachment. The filter cell allows ease of eyepiece changes without threading/unthreading the filter, and is also easier to change-out than the standard 2″ filter cell with gloves on, for cold-weather observing.
Aids in viewing of extremely faint nebulous objects such as the Horsehead, Cocoon and California Nebulae. In many cases, the Lumicon Hydrogen-Beta Filter is the ONLY way to view these objects. Recommended for 8″ or larger telescopes.
Lumicon filters remain the world’s best and strictest quality control standards are employed throughout the production process. Each Lumicon Hydrogen-Beta Filter is individually inspected and proudly inscribed with the percentage of light transmittance of the H-Beta emission line.