First Light - Celestron 9.25 SCT

[dweller25]

My wife and I have had this scope for a couple of weeks now, but last night was the first time we have had chance to use it properly.

The scope is mounted on a Celestron CG5 and is non motor driven. A lot has been said about this OTA/mount combination being a poor one, but our experience is that even at powers up to x313 vibration settles in around 2 seconds if you hit the mount/legs or tube. Vibration due to focussing does not occur - probably due to the very smooth focussing knob. Image shift during focussing at x313 is nil - another worry I had that has not materialised.

When the scope was delivered we checked it's collimation - it was way out, so job#1 was to sort it out. Thanks to the really great info on the net this was soon accomplished aided with a new set of Bobs knobs (which are brilliant and should be supplied as standard) and collimation is now very good - cannot verify at very high powers as the seeing in our locality is poor, but at x313 it looks spot on.

We had big reservations about the weight of this setup as I have a bad back so setting up involves the wife carrying the tripod/weights and OTA into the garden separately which is working out just fine for me . Before use we allow the scope to cool for at least two hours.

Many years ago we owned a motor driven 8.5 inch F5 Newtonian and were keen to compare its performance to the 9.25 inch SCT.

Sadly the planets are not favourable at the moment so we spent our time last night looking at a few Messiers. First up was the obligatory M31 - easily found and we could also see M101, oddly we could not see M32 !! - the view was very much as we remembered it in the 8.5 F5.

The next target was the ring nebula in Lyra - this was a big surprise, we could push the magnification up to x150 and still get a reasonable image - although it was better at x100. No central star could be seen though. This was a much better view than we could remember in the 8.5 F5.

Slewing down and to the left we soon found the dumbell nebula - this was quite bright but no colour could be seen.

Moving round to the west M13 was an easy find and looked really good even at x150 the globular looked great - quite bright and sharp - this was much better than the old 8.5 F5.

We had to stop after just 30mins as the front corrector dewed up. We have an astrozap on order which should be here early next week with a bit of luck.

Overall we are very happy with our purchase, star images are very sharp, Vega was almost dazzling to look at and the overall mount/tube combination is good. This is a better scope than my old 8.5 inch F5 newt, which is what I wanted.

However I am not too impressed with the feel of the CG5 mount - it's functional but a bit rough and ready and no motor drives is a pain. We have therefore ordered a HEQ5 which whilst a little heavier should still be manageable and the motors will add a new dimension to the ease of viewing. I plan to put the HEQ5 head on the CG5's 2" legs for optimal stability.

Roll on Christmas and Mars.

Regards,

David.

[cygnusx1]

I hear only good things about the 9.25, i'm looking for a second hand one myself, though they do seem hardish to find.