The Baader UHC-S Nebula Filter is a visual and photographic Light Pollution Reduction (LPR) Nebula filter that delivers a “happy medium” in light transmission with enough light for smaller telescope openings (100mm aperture) at the same time with the high contrast of a classical UHC filter. The filter produces a much brighter image with superb contrast than a conventional Nebula filter. It has a transmission of >95% (at ~500nm and ~650nm) and also gives realistic star colour results too! Light pollution from street lights is blocked carefully. The filter is the sensible addition to all previous deep sky and UHC filters.
Each individual filter is optically fine-polished to 1/4 wave and are hard coated. All Baader filters sport scratch resistant hard coatings which can be cleaned repeatedly throughout their entire lifetime as many times as needed – preferably with Baader Optical Wonder cleaning fluid.
Baader filters are individually made and not cut out of a larger plate-glass “master” (which is a typical manufacturing process for economy filters) as cut-out filters exhibit micro-cracks around all edges and capillary action between glass and coating layers will lead to premature ageing due to moisture deposition. All Baader filters have individual coating sealed edges, impermeable against ageing because the penetration of moisture is impossible.
Baader filters are continually tested to comply with MIL-specifications. One common test process is to boil the test specimen for one hour in salt water. Baader filters remained completely intact as opposed to filters drilled out of large glass plates.
|TRANSMISSION RANGE||multiple bands (see spectral image)|
|FILTER THICKNESS (WITHOUT CELL)||2 mm / 3mm|
|AR-COATING||dielectrically coated, planeoptically polished|
|FILTER USAGE||Contrast Enhancement, Light Pollution Reduction, Luminance|
|FILTER MOUNTED||Mounted (LPFC 6mm)|
|TYPE OF FILTER||Bandpass|
|SINGLE OR SET?||Single Filter|
|FILTER SHAPE||round / square|