Hi
Would like to know if anyone here has used any particular brand of field flattener for an 80mm OTA and can recommend it?
I've tried the HoTech one (purchased from MyAstroshop) on an 120mm ED OTA and it works a treat, however it just does'nt do the job on the Equinox 80mm ED OTA
With & without the FF, the 80mm has elongated stars in all the four corners of the image and I reckon that I lose about 33% of the image because I'd have to crop it off - though I wonder if by using a 2.5" focuser (MoonLite custom LF version) instead of the 2" one that I've actually created the problem for myself - on the other hand could the spacing to the CCD chip be a factor? ie it is different for a 120mm than for an 80mm refractor?
The FF is currently just between the CCD camera and the focuser like this:
CCD -> FF -> Ext tube -> into the MoonLite focuser
Any help in pointing me in the right direction would be greatly appreciated
TIA
Cheers
Bill