Baader Planetarium 1.25" Colored Glass Filter Set - Optically Polished. Incudes: Red (610nm), Orange (570nm), Green (500nm), Yellow (496nm), Blue (470nm), Blue-Violet (435nm).
These new premium 1.25" color filters feature high-transmission, plane-parallel, optically polished glass, multi-coated on both surfaces. True plane-parallel surfaces eliminate ghost images at the eyepiece. The fine optical polish allows the filters to be inserted anywhere in the optical path without introducing astigmatism and other defects. Thus they can be used with the Baader Giant Binocular Viewer or other similar products without concern about degradation of your image.
Filters come in the following colors: Red (610nm), Orange (570nm), Green (500nm), Yellow (495nm), Blue (470nm) and Blue-Violet (435nm). Transmission efficiencies for the Red, Orange and Yellow filters is approximately 95% within their passbands. Transmission efficiencies for the Green, Blue and Blue-Violet filters is approximately 65% at their center wavelength.
All filters have standard 1.25" eyepiece filter threads. Filters can be threaded together to allow stacking for narrower passbands.