About the Celestron UHC/LPR Filter - 2"... The Celestron Ultra High Contrast /Light Pollution Reduction Filter is designed to selectively reduce the transmission of certain wavelengths of light, specifically those produced by artificial light. This includes mercury vapor, and both high and low pressure sodium vapor lights and the unwanted natural light caused by neutral oxygen emission in our atmosphere (i.e. sky glow). The Celestron UHC/LPR Filter has improved contrast over the typical broadband filters. Sky background is darker, and contrast of emission nebulae are noticeably improved. The advanced technology coatings enable the filter to achieve an outstanding transmission of over 97% across the entire bandpass, with total blockage of prominent light pollution lines. The perfect filter for viewing nebula from light polluted skies, or for boosting the contrast of nebula from dark sky sites. In addition to it's optimum spectral and optical characteristics, the Celestron Ultra High Contrast /Light Pollution Reduction Filter offers important features that set it apart and result in the highest quality celestial views: The multi-layer dielectric coatings are plasma assisted and Ionbeam hardened using the latest technology for durability and resistance to scratching. Improved transmission of the Celestron UHC/LPR Filter translates to maximum image brightness and contrast. Users of smaller, 4"-11" telescopes will especially appreciate the high efficiency, and larger scope users will love the rich star fields and detailed subtle nebular shadings that are left intact. The high transmission, sharp cutoffs, and more moderate 60nm passband of the Celestron UHC/LPR Filter retains a more natural view, yet significantly boosts overall contrast. Imagers will appreciate the broader bandpass and inclusion of an extremely efficient H-Alpha passband (656nm). Celestron UHC/LPR Filter - 2" Features... Ion beam hardened using the latest technology for durability and resistance to scratching Advanced technology coatings enable the filter to achieve an outstanding transmission of over 97% across the entire bandpass Designed to selectively reduce the transmission of certain wavelengths of light, specifically those produced by artificial light High transmission, sharp cutoffs, and more moderate 60nm passband retains a more natural view, yet significantly boosts overall contrast Improved transmission translates to maximum image brightness and contrast Celestron UHC/LPR Filter - 2" Specifications... Filter Type: Ultra High Contrast / Light Pollution Reduction Format: Round Mounted Size: 2" Construction: Threaded Aluminum Cell Passband: 60nm Transmission: 97% Celestron Product Number: 94124
