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
Light blue bandpass filter 470 nanometres: Filter for visual and photographic planetary observations
- For observing high clouds on Mars, for increasing the contrast of haze layers at the terminator of Mars (violet clear glass)
- Shows reddish structures darker, therefore the ideal filter for observing the Great Red Spot on Jupiter - also shows details in Saturn's rings better
- For observing structures in the atmosphere of Venus, also highlights fine details in gas tails of comets
