Set of 3 Ultra Highspeed filters Ø 31 mm - 3.5/4 nm Cmos Optimized Baader Planetarium

Baader H-alpha / O-III / S-II f/2 ultra high speed filter set 31mm x 2mm - Top grade 3.5/4 nm #2961681. FWHM (to harmonize H-alpha exposure time with O-III / S-II), recommended for extremely fast optical systems from f/3.4 to f/1.8. Specially designed for special filter requirements when used with fast optics such as astrographs Celestron RASA. For the highest contrast even with the strongest light pollution, minimizes star size, emphasizes the finest nebula details, indispensable under Bortle 9/8/7/(6) skies. Hard-coated, planoptically polished Reflex-Blocker™ with sealed coating edges ( Life-Coat™). Optimized for modern CMOS cameras, but excellent for CCD camera technologies. Increased contrast. Narrower and narrower pass bands. Reflex-Blocker™ coatings, for the greatest elimination of halos, even in the most adverse conditions related to auxiliary optics. FWHM in each filter category carefully designed to allow 1:1:1 exposures, combined for typical CMOS quantum efficiency and s/r ratio. Filter thickness identical to existing standards, with extreme care for parafocality. Blackened edges all around, to additionally eliminate any reflections due to light falling on the edge of a filter. Each filter individually coated , with sealed coating edge (NOT cut from a larger plate with exposed coatings, read more ). Life-Coat™: increasingly hard coatings to enable a coating that will not age for life, even in the harshest environment.

MANUFACTURER Baader Planetary
SKU (#) 2961681
EAN CODE 4047825104113
NET WEIGHT (KG) 0.18
COLOR Black
TRANSMISSION RANGE H-alpha / O-III / S-II
FILTER THICKNESS (WITHOUT CELL) 2 mm
HBW (HALF BANDWIDTH) 3,5 nm (H-alpha) / 4 nm (O-III / S-II)
CWL (CENTER WAVE LENGTH) 656.3 nm / 500.7 nm / 671.7 nm
AR-COATING Reflex-Blocker™ hard-coated, planoptically polished
SPECIAL FEATURES CMOS optimized with Life-Coat ™
FILTER SIZE 31 mm
FILTER USAGE CMOS, CCD, H-alpha, O-III, S-II
FILTER MOUNTED Unmounted
FILTER TYPE f / 2 Ultra-Highspeed
SOLO OR SET? FILTER SET
FILTER SHAPE round