Baader colour filters are carefully manufactured for amateur astronomical use. The glass is finely polished to be plane-parallel. These filters far exceed the quality of the usual "roughly polished" (= hot-blazed) colour glass filters.
Thanks to their fine optical polish, these filters can be used at any point in the beam path – well in front of the focal point – (e.g. in front of a binocular attachment!) without causing optical errors (astigmatism) or otherwise impairing the image in any way!
Further special features of Baader filters:
- Elaborate frame with the largest possible free opening to prevent vignetting
- CNC-milled "crown grip" – offers excellent handling comfort
- 7-layer anti-reflection coating on both sides with only 0.25% residual reflection per surface
Yellow long-pass filter 495 nm: Suppresses the secondary spectrum (blue component) in achromatic and semi-apochromatic refractor lenses, thereby increasing image sharpness!
- The contrast of the surface of the Moon and Mars is increased.
- The filter also increases the contrast between the bands and zones of Jupiter's clouds
- With larger instruments with an aperture of 8 inches (200 mm) or more, details on Saturn can be seen.
