Hi,
My previous thread I put in Deep Sky for some reason,
http://www.iceinspace.com.au/forum/s...ad.php?t=39567
however, I tried a few combinations of spacing and lens
arrangement for the 30mm objective....not really anything
outstanding.
Coma was pretty bad, and it's quite disappointing, as this
was my trusty FR from webcam days for years on the 8"F7 Newt.
It just doesn't suit the GSO and it's short F.L.
In the best spot I get vignetting, so I made a 2" barrel on my lathe
to sit it in.I adjusted spacings and the 2nd shot below from Jan 04
is the best from a few nights testing.
Then I tried a 40mm doublet I have, that worked better. Pic 3 from Jan 08/09.
Still some slight coma, not a really good night to test it. Stars were
blurring on a 5 sec exposure with the DSI.
Compared to my Prime/Newt focus shot from Dec 02 2008, they don't
even compare.....Dec 02 was an outstanding night of seeing
(Pic 1)
Pics also of the 2" adaptor I made. Old VCR heads are a great source of 2"
Aluminium stock!
Steve