: Hello : Televue makes a richfield corrector for fast newtonians I have 2 : one for visual and one for prime focus astro photo. you might find a 2" big barlow : and the paracore will work fine, my newt is f3.8 and with the paracor visual is very nice : minor coma like that of an f7 exists at prime focus photo. : Hi,

: I am planning on putting together a 12.5" F2.92 RFT : (primary is a C/Cass mirror)and was wondering what can I do about the coma? would a Celestron CC work? or do I need a special CC to cover a full 45mm dia. circle of illumination which is the diagonal of a 24 x 36mm 35mm frame. Any help guys? Secondary is 3.1".

: TIA

: Jim