Thanks for the advice so far everyone. I managed to get the scope out last night when we had 10 mins of clear sky of sorts. The scope was collimated using the 35mm film canister at this point.
Without waiting for the scope to cool the star test showed an even circle with the black (secondary) centered correctly at both ends of focus. I could not however see any 'Airy Disc' that I have read about, mainly turbulence. Saturn looked pin sharp! So should I be happy?
These images describe more accurately what I meant in my initial post about position of the secondary. This from the
website - "
You should note that fast scopes of f5 and above are less tolerant of collimation errors and they also show slightly offset collimation patterns."
http://www.astro-baby.com/collimatio...ollimation.jpg
http://www.astro-baby.com/collimatio...mation%202.jpg
That is what I am seeing and concerned me initially i.e that I could not get everything centred. This seems to explain why. Any thoughts.
BTW I got the laser collimater out after the star test and it (as always so far) didn't agree that the collimation was spot on - the secondary being out by a fair bit!
Cheers
Dave