Baader 2" Orange 570 nm Longpass Eyepiece Filter 

Freedom from Ghost images, even when stacked. Striae-free substrates are polished parallel to 30 seconds of to avoid wedge errors. Finest 7-layer hard multi-coatings on both faces feature 0.25% residual reflections (Baader filters are unique, no other colored filter incorporates anti-reflection multi-coatings). The coatings are also different for each of the filters, in order to match the coating performance to the filter curve of each color. This maximizes the transmission and minimizes reflections.

Extremely High Transmissions deliver maximum contrast to highlight planetary details, even when smaller telescopes are being employed. 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).