Celestron Light Pollution Imaging Filter for 8″ RASA – 93614 Celestron

Celestron Light Pollution Imaging Filter for 8″ RASA

The quality of astronomical image contrast suffers substantially when light pollution levels are too high. With ultra fast instruments like the 8″ RASA, this is particulary true since the sky background saturated extremely quickly. Light pollution “noise” overpowers the “signal” from your target celestial object to make capturing strong detailed images a much harder task. The solution is this Light Pollution Imaging Filter for the 8″ RASA which fixes this problem by obstructing sources of light pollution while allowing light from deep sky objects to be transmitted resulting in bright objects with great detail and high contrast that stand out against the black sky background.

Fortunately, many sources of light pollution have relatively discreet emission spectra as they emit primarily at specific wavelengths of light. By strategically blocking these wavelengths, this filter greatly reduces the effects of light pollution without degrading overall image quality.

Light from some of the most frequent light pollution culprits in the visual spectrum (400-700 nm) such as high and low pressure sodium-vapor and mercury-vapor streetlamps, as well as natural airglow resulting from oxygen in the atmosphere is blocked by this Light Pollution Imaging (LPI) Filter for 8″ RASA. This LPI filter blocks only distinct spectral areas instead of wide regions like some light pollution filters do. Image brightness and color brightness is thus maintained. Furthermore, specific emission nebulae wavelengths like 656 nm for h-alpha, 486 nm for h-beta, 496 nm and 501 nm for OIII, and 672 nm for SII, are highly transmitted to ensure decreases in image brightness for those objects will be minimal.

This filter fits directly into the internal filter mount in the 8″ RASA’s front lens cell where the optical window normally mounts. By removing the clear window and replacing it with the LPI filter, optical performance for the entire system is preserved.

Each Celestron LPI filter comes with a plastic storage case for safely storing either the filter or the placeholder glass that came with your RASA when not in use. You will also receive a spectral transmission graph unique to your specific unit to verify its performance.