Baader 6.5nm f/2 Highspeed Filter-Set – CMOS-optimized (H-alpha / O-III / S-II)

The actual dimensions are 65mm length on each side with tolerance + 0 / - 0.2mm

If the filters are used outside the specified aperture ratios, there is a strong loss of contrast of the photographed object which increases towards the edges of the image.

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