The Baader solar continuum filter (540 nm) has long remained a secret tool for astronomers conducting professional observations of the Sun.
The unmatched contrast of the photosphere's details is achieved by an extremely narrow bandwidth of 8 nm. It works like a monochrometer, eliminating the effects of atmospheric turbulence, allowing for very stable images.
• greatly increases the contrast of the image
• eliminates image imperfections related to seeing (atmospheric stability)
• monochromaticity of the filter eliminates errors of optics related to chromatic aberration (the picture is as good in the achromat as in the apochromatic triplet)
Note: an eyepiece filter, used exclusively in conjunction with the AstroSolar Baader or other objective filter!