Baader 3.5 / 4nm f/2 Ultra-Highspeed-Filterset 36mm – CMOS-optimized (H-alpha / O-III / S-II)

Highlights 

• 36 mm x 2 mm Baader CMOS H-alpha / O-III / S-II f/2 Ultra-High-speed Filter Set – Premium Grade
• 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 highest contrast even at strongest light pollution, minimizes star size, emphasizes finest nebula detail – indispensable under Bortle 9/8/7/(6) skies
• Reflex-Blocker™ hard coated and Plane-optically polished – with sealed coating edges (Life-Coat™)
• Blackened edges all around, with 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

Description 

 This new generation of Baader CMOS-filters features:

 

Increased contrast

Ever more narrow band-passes

Reflex-Blocker^™ coatings, for largest ever freedom from halos, even under most adverse conditions concerning aux-optics

FWHM on each filter category carefully designed to allow for 1:1:1 exposures,

matched for typical CMOS quantum efficiency and s/n ratio

Identical filter thickness to existing standards, with utmost care for remaining Par focal

Blackened edges all around, with filter-lead-side-indicator in the form of a black front side outer rim, to additionally eliminate any reflection due to light falling onto the edge of a filter

Each filter coated individually, with sealed coating edge (NOT cut out of a larger plate with coatings left exposed, read more)

Life-Coat™: evermore hard coatings to enable a non-aging coating for life – even in a most adverse environment

 

Specifications 

 

Manufacturer	Baader Planetarium
SKU (#)	2961682
EAN Code	4047825104120
Net weight (kg)	0.19
Suitable for f/ratio	< f/2.3
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 (Central Wavelength)	656,3 nm / 500,7 nm / 671,7 nm
AR-Coating	Reflex-Blocker™ hard coated, Plane-optically polished
Special Features	CMOS-optimized with Life-Coat™
Filter size	36 mm
Filter Usage	CMOS, CCD, H-alpha, O-III, S-II
Filter mounted	Unmounted
Type of Filter	f/2 Ultra-High-speed
Single or Set?	Filter-Set
Filter shape	round