View Full Version here: : Keyhole with Celestron 9.25SCT Prime Focus
Robert_T
15-06-2008, 10:57 AM
Picked up a 0.63x reducer for the C9.25 (IIS classifieds of course;)) and thought I'd give it a whirl with the Canon 40D last night - Eta the obvious target...near full moon about 50deg away so far from ideal.
With the C9.25 and ZS66SD piggybacked as guidescope I was stressing the capabilities of the LxD75 mount.. had to add a third weight. Took some time fine tuning balance - actually I was surprised how well the mount actually handled nearly 15kg of stuff:) , though dont think I'll be making a habit of this until I get a better mount.
I wanted to run short exposure to limit guide issues so bumped the ISO up to 1600 and ran a series of 2 minute prime focus pics with the 0.63 reducer and IDAS-LPS filter. Took about 16 shots but graded to best 10 to match the 10 darks and 10 flats I took at dusk.
Processed and combined in Images Plus and with exposure and colour balance selectively tweaked to bring up the red.
Comments and advice always welcome.
Hagar
15-06-2008, 04:04 PM
Hi Robert, Just had a look at this shot. Nice image. The finer detail is brought out well with the larger appature. The 6.3 focal reducer is what is needed for the long focal length and high F rating of the 9.5.
Great detail, longer and more shots improves Signal to noise ratio and gains more dpth of field in the image.
Well done.
Inmykombi
15-06-2008, 06:59 PM
A stunning image.
Lots of detail and a nice dark background.
Well done
Geoffro
Lester
15-06-2008, 07:23 PM
Hi Robert,
I like your image, and as Doug said.
Well done.
Matty P
15-06-2008, 08:09 PM
Nice image Rob, well done.
Nice colour and detail.
:thumbsup:
Very nice Robert, the stars are nice and sharp and the details look great.
A fine image.
Robert_T
15-06-2008, 10:03 PM
Thanks very much guys for your kind comments.:)
I must confess that I'm quite impressed myself (and I know there's way better out there) with what can be achieved with these DSLR's under what would have been impossible conditions in the film era:thumbsup:
cheers,
Rob
Tamtarn
16-06-2008, 12:21 PM
Very nice equipment you have there Robert. The LXD75 handled things quite well.
Interested in your set up. We're thinking of upgrading to a longer focal length ourselves soon and the 9.25 seems a good choice.
Good image by the way :)
Robert_T
16-06-2008, 12:41 PM
Thanks guys, the LXD75 did admirably, but it was really stretching it's capabilities. It's the later version with 2inch stainless tube tripod legs otherwise there would have been no chance;). I'm thinking an EQ6 is on the horizon:whistle:
The C9.25 is certainly impressive for planetary. Hadn't though much about it for deep sky, but with the 0.63 focal reducer it seems to do a good job and it is nicely compact. A C11 might be even better and not much different in weight:D
Tamtarn
16-06-2008, 04:52 PM
Had seriously considered the C11 Rob but with more focal length again than the 9.25 tracking would have to be absolutely spot on and we don't want to upgrade the EQ6, so the C9.25 EQ6 combo should work really well :)
You won't regret getting an EQ6 they're a great mount :thumbsup:
By the way your image with the focal reducer we assume is the full frame and not cropped at all ??
D&B
Robert_T
16-06-2008, 05:31 PM
:thumbsup:
Sounds great. I did slightly crop the image... I think I'm suffering some field distortion in the very corners of the image. See the thread below to see an uncropped single exposure frame. cheers, Rob
http://www.iceinspace.com.au/forum/attachment_browse.php?a=43931
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