Description
- 1¼" x 2 mm Baader CMOS H-alpha / O-III / S-II f/2 Ultra-Highspeed Filter Set – Premium Grade – with 1¼" (28,5 mm) filter thread
- 3.5 / 4 nm FWHM (to harmonize the exposure time from H-alpha with O-III / S-II), recommended for extremely fast optical systems from < f/2.3
- Specially designed for the special filter requirements when used with extremely fast f/2 optics like the Celestron RASA astrographs
- For the highest contrast, even at the strongest light pollution, minimizes star size, emphasizes finest nebula detail – indispensable under Bortle 9/8/7/(6) skies
- Reflex-Blocker™ hard-coated and planeoptically polished – with sealed coating edges (Life-Coat™)
- Blackened edges all around, with a filter-lead-side-indicator in the form of a telescope-sided black outer rim
- Optimized for modern CMOS cameras, but likewise excellent for CCD camera technologies
- Mounted in Baader Ultra Low Profile (ULP) filter cell – 5,5 mm height