Baader 3.5/4nm f/2 36mm Ultra High Speed Filter Set, Optimized for CMOS (H-alpha/O-III/S-II)
Baader CMOS H-alpha / O-III / S-II f/2 36mm x 2mm Ultra High Speed Filter Set - Premium Grade
3.5/4nm FWHM (to harmonize the exposure time of H-alpha with O-III/S-II), recommended for extremely fast optical systems greater than f/2.3
Specially designed for special filter requirements when used with extremely high aperture f/2 optics such as Celestron's RASA astrographs.
Enables the highest contrast even in the strongest light pollution, minimizes star size, makes the finest detail of the nebula accessible - indispensable under Bortle skies 9/8/7/(6)
Plano-optically polished, hard-coated Reflex-Blocker™ with sealed coating edges (Life-Coat™)
Blackened edges all around, with front filter indicator in the form of a black outer rim on the side of the telescope
Optimized for modern CMOS cameras, equally suitable for CCD camera technologies