"The Baader UHC-S Nebula Filter 2"" excels at delivering a high-contrast and natural view of emission nebula without excessive dimming and loss of background star fields. It is the perfect filter for viewing emission nebula from light polluted skies, or for boosting the contrast of nebula from dark sky sites. The advanced technology coatings enable the filter to achieve an outstanding transmission of over 97% across the entire passband, with total blockage of prominent light pollution lines. This translates to maximum image brightness and contrast. Owners of smaller, 4""-10"" 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 Baader UHC-S manages to improve on the contrast of the typical broadband or so-called ""Deep Sky"" filters. Sky background is darker and contrast of emission nebulae are noticeably improved. Most other ""UHC"" filters tend to excessively darken the sky and star fields, leaving the nebulae looking artificial and flat, set against an empty background. The high transmission, sharp cut-offs and more moderate 60-nm passband of the Baader UHC-S filter retains a more natural view, yet significantly boosts overall contrast. Imagers will appreciate the broader passband and inclusion of an extremely efficient H-Alpha passband (>99% @656nm), as well as the extreme optical quality."