Baader Planetarium 2" Red Eyepiece Filter - 610 nm Longpass - FCFR-2

Freedom from Ghost images, even when stacked. To avoid wedge errors, striae-free substrates are polished parallel to 30 seconds. First-class 7-layer hard multi-coatings on each face have 0.25% residual reflections. Baader filters are unique in this way as no other colored filter includes anti-reflection multicoatings. In addition, these coatings differ depending on the filter so that the coating performance matches the filter curve of each color. This increases 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. Baader 2" color filters are stackable without image deterioration or ghosting, for even more narrow passbands. You can also combine them with other Baader filters for many potential possibilities.

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).