The Baader Narrowband S-II Low-Pass Filter is the first choice for astrophotographers - if they want to get excellent images optimised for the most contrasty CMOS but also excellent images on CCD at S-II wavelengths. The filters have excellent light transmission in the S-II wavelength range, while at the other "unwanted" wavelengths they cut off the light completely. They guarantee excellent results when used with binoculars from f/10 to f/3.5.
The excellent glass material and machining of the filters promise excellent contrast and sharpness. The coatings are applied to the glass material using state-of-the-art tools that guarantee an ideal transmission range. Anti-reflective coatings contribute to excellent imaging and the surfaces are treated to make the glass material scratch-resistant.