[g__day (Matthew)]

Personally I really like the C9.25 optically. I haven't had too many other scopes to compare it to (a 6" Newt, a 5" MAK and a 80mm refractor), but it has a beautifully flat field and finds focus well. My next scope will probably be a 4" - 5" apo once I've saved up a bit (alot)!


So given my seeing conditions and limited experience with viewing and not having the chance to view through a broad range of different scopes
I am quite happy with the C9.25. It performs to spec and is a delight to use.

The only scope that every left me with a OMG chill was Zane's 24" Obsession at Magellean - under very dark skies it really was a magical experience!

I've loked through 16" SCT at Macquarie Uni's labs - and 10" SCTs - but too long ago to really recall with detail how well they performed.

I think the EQ6 is a practical starting platform for imaging so long as you keep it within its capabilities. As I am finding on a mount that costs circa 3 times the eq6 with similar carrying capacity - longer > 10 minutes
imaging at long focal length (2.3 metres) is quite tricky - my auto-guiding is not giving me what I need yet. I just checked to day on a shot with streaks I'm 20 arc seconds of RA drift adjustments out in my guiding of a 20 minute duration shot. So 1 arc second per minute RA drift is enough to ruin things.


In the shot below - the 150 mm length is 30 arc minutes so 1 mm = 20 arc seconds. By my ruler bright stars are 1 mm in diameter ~ 20 arc seconds, and drift is 1 mm - making stars into clyinders 2mm long - 20 20 arc seconds drift in a 20 minute shot. So close to perfect but so far away!

Why I am out is what I am working on now - it might be optical limits of my gear, seeing conditions, poor tuning of my set up etc. Until I can track the source of my problem I can fix it and see where the limit of my gear is. The point is your choice of targets and calibre and tuning of your gear limits what you will be able to achieve. Keep within those limits and you'll be happy.

Imaging is like this - your choice of target defines what you can aspire to on a certain level of gear. At present I'm hooked on faint planetary nebulae - so I've picked up the hard basket!