BAADER TURBO FILM 127 X 51 cm QHYCCD-IP A female M60 thread to

A female M60 thread to male M42 thread (optical thickness of 7mm)

Auto guiding speed

9mm and a resolution of 20

05 mm for 50mm  Optical flatness 1/4 λ (wavefront) Bandpass transmission >95% Off-band transmission OD3 @ 300-1050 nm Coating Double-sided multilayer nano-coating Surface quality 60/40 (in accordance with US military watch MIL-O-13830) Parallelism <30" Glass type Monolithic optical substrate (non glued) Filter size Mounted 1

where the key factor is a large aperture for little money

BAADER TURBO FILM 127 X 51 cm QHYCCD-IP A female M60 thread toBaader Turbo Film is highly precise protective film used as the base for AstroSolar safety film and is available in sheet form for DIY construction. This is not cheap Mylar, but a monomer film that Baader have selected after trying over 200 different substrates on their Zeiss autocollimator. This particular film has been used as an optical membrane in nuclear and particle physics experiments by prominent German science institutes, and has been further