Quote:
Originally Posted by Matty P
Will I benifit from purchasing a Crayford focuser for my SCT?
Do any SCT owners use them?
 |
I have a JMI NGF crayford.
For imaging, a crayford will help you focus precisely with minimal image shift.
However it adds a fair bit of length to the optical system. You may not have enough forward travel in the SCT mirror to reach focus with a DSLR. I cannot reach focus when I use the NGT with the C8 and an f6.3 flattener. Without the flattener the DSLR and NGT will reach focus but of then of course there are issues with field flatness.
Hope this helps.
Cheers,
Rob