ULTRA HIGH CONTRAST (CELLULE SCT) / ULTRA HIGH CONTRAST (SCT REAR CELL)
The original Lumicon Cassegrain 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. Recommended for telescopes 8" and larger in aperture.
The Lumicon Cassegrain Ultra High Contrast Filter threads onto your telescope's SCT rear-cell, and presents male SCT threads for accessory attachment. The Cassegrain filter cell allows you to change eyepieces 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.
To ensure that your Lumicon filter remains the World's Best, the strictest quality control standards are employed throughout the production process. Each Lumicon Ultra High Contrast Filter is individually inspected and proudly inscribed with the percentage of light transmittance of the OIII and H-beta emission lines.