S-II 1¼" Ultra-Narrowband-Filter (4nm) – CMOS-optimized

Baader S-II 1¼" Ultra-Narrowband-Filter (4nm) – CMOS-optimized

• 1¼" x 2 mm Baader CMOS S-II Ultra-Narrowband Filter – Premium Grade – with 1¼" (28,5 mm) filter thread
• 4 nm FWHM, recommended for optical systems from > f/3.4
• 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 planeoptically 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
• Mounted in Baader Ultra Low Profile (ULP) filter cell – 5,5 mm height

This new generation of Baader CMOS-filters features:

• Increased contrast
• Ever more narrow passbands
• 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 parfocality
• Blackened edges all around, with filter-lead-side-indicator in the form of a black frontside 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