Baader S-II Narrowband-Filters (6.5nm) – CMOS-optimized

If your optics is so well color corrected that parvocality only means to keep the filter thickness the same as befoire, then indeed the new CMOS-optimized filters are parfocal to all Baader-filters as we try to keep the substrate thickness consistent troughout all our filters. Otherwise we want to confirm that the new CMOS-optimized filters are on a much higher level of coating technology compared to the previous ones.

Our largest cell mounted filters measure 2" (50.8mm) in mechanical diameter (having a metric thread of M48). The optical clear aperture is 46 mm. In order to ease the adaptation of our 2" filters onto most camera lenses, we do produce a 2" filter-holder, to convert from the ASTRO-2" Standard (M48) into a more common photo-standard of SP54 mm ("SP"means this is not a metric thread). For adapting any cell mounted Baader 2 inch Filter onto a camera lens with 52mm front filter thread you will need: #2408166 Baader DSLR 2" Filter-Holder M48 / SP54: https://www.baader-planetarium.com/en/baader-dslr-2%22-filter-holder-m48sp54.html #2958052 Baader Lens-Adapter-Ring SP54 / M52: https://www.baader-planetarium.com/en/baader-hyperion-dt-ring-sp54m52-for-dtadapter-iiandiii-and-hyperion-eyepieces.html Based on the SP54 thread, we offer many more adapters for various camera threads, our so-called Hyperion DT-rings. https://www.baader-planetarium.com/en/catalogsearch/result/?q=sp54