Baader Planetarium 2" Yellow Eyepiece Filter - 495 nm Longpass - FCFY-2

Baader 495 nm Longpass Filter - 2" Yellow

Freedom from Ghost images, even when stacked. The substrates of this Baader 2" filter are free of striae and polished parallel to 30 seconds in order to avoid wedge errors. It features the finest hard 7-layer multi-coatings on each face with 0.25% residual reflections. Baader filters are special in this regard as all competing filters are without anti-reflection multi-coatings. Futhermore, the coatings differ for each filter so that they match the coating performance to each color's filter curve to increase transmission while decreasing reflections.

Extremely High Transmissions provide maximum contrast to bring out planetary details, even when smaller telescopes are used. The three Baader longpass filters (Red, Orange, and Yellow) have peak efficiencies of 98%, while the three Baader bandpass filters (Green, Blue, and Dark Blue) top out at 70%.

Carefully designed spectral characteristics. In order to deliver even narrower passbands, these color filters from Baader can be stacked without ghosting or image degradation. Additionally, they can combine with other Baader filters to enable many interesting contingencies.

No reduction in sharpness, even at high magnifications or when using the filter far ahead of the focal plane (ie, digital imaging, or in front of a diagonal or binoviewer).