Quote:
Originally Posted by RobF
Just remembered another way I double checked where my Newt's focal plane was - connected my MPCC corrector to my 450D (DSLR) and with OTA pointing out the window during the day, then just moved the camera in and out of the drawtube by hand until reaching focus according to the viewfinder. Of course, would work just as well at night on a bright star.
Might be another option....
|
Hi Rob,
Yes - I could get focus with a DSLR 5 months ago.
The problem was to get it with my imaging train.
I really admire Oleg Bryzgalov in the Ukraine.
https://m.flickr.com/#/photos/olegbr/19380596936/
His pictures are simply amazing.
He has a custom built 10" f3.8 - so it's close to an f4 that I have.
He's using a different imaging train:
camera QSI-660wsg with Tevevue Paracorr-2
(L and Ha filters) and QSI-583wsg with TS 2.5″ 0.95x Wynne corrector (RGB filters). Off-axis guidecamera QHY5L-II.
I don't know how he worked it out but I do know that the experts usually
have a temporary way to work out the best focus position.
They use those results to correctly place their final chosen mirror assembly with holder.
I want to copy Oleg's mirror holder design.
I have the plans for it.
I also may need to change to a Tevevue Paracorr-2 instead of my RCC1.
In such cases a temporary inside aluminum sleeve must be the way to go -optimise everything.
You can really make a 10" f4 sing if you can get it just right.
cheers
Allan