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View Full Version here: : Jewelbox up close


multiweb
03-05-2009, 04:20 PM
Still playing with my new C11 when weather allows :whistle: and learning a few things. I bought a 8x50 finder so it's way easier for me to find stuff now :lol:. Still targeting the "easy ones" with clean star fields so I can see star shapes and iron out a few problems.

Did 24x1min on NGC 4755 last friday night. Got the guiding 100% finally sorted out on the OAG so that's one good thing out of the way. I'm also getting there with collimation and focus although it's more tricky. I need to check my focus more often. I suspect as the scope moves so does the mirror and focus is affected, even collimation. Things are ok when imaging at the zenith right up but it changes quite rapidly when imaging anything under 40 degrees. So I'll have to take that into consideration from now on when planning an imaging session.

There's a full frame available at: http://www.multiweb.com.au/astro/ngc4755_f.jpg [filesize: 4.7MB]

Taken on a C11 at prime focus(f/10) with a QHY8 and OAG was QHY5 with a Meade T piece on a G11. Comments/tips most welcome. Thanks for looking and I'd also like to hear from users with "heavy mirrors" how you deal with focus/collimation changes. (if any) :)

peter_4059
03-05-2009, 04:28 PM
Sure is up close Marc. Plenty of faint stars there also.

Hope you sort out the mirror.

Peter

Tilt
03-05-2009, 05:20 PM
Ah moved up from the ED80 I see. Nice image there Marc.

Michael

gregbradley
03-05-2009, 06:35 PM
An excellent image of a difficult object.

Are there a couple of small planetary nebulas there as well? Looks like one above the bright upper right hand side star.

Greg.

multiweb
03-05-2009, 06:46 PM
Thanks guys :thumbsup: .. and thanks Greg. Yeah that'd be cool if it was a PN but I have a sneaking suspicion it's a reflection. :whistle:

RB
04-05-2009, 10:47 AM
Nicely done Marc.
Very good colour in the stars.

I suspect it's reflection too, rather than a PN though.

Looking forward to more from your setup mate.

:thumbsup:

multiweb
04-05-2009, 11:40 AM
Thanks Andrew :) It was bright enough . Goto is my bigqest problem at the moment. I'm sort of "mobile" without an permanent set-up and the C11 needs precise pointing. I've been looking for M83 for a while now ... Is it still there? :lol:

bluescope
04-05-2009, 01:52 PM
Nice image of one of my favourite clusters Marc ... I like that you captured the colours of the two blue and one red star at the core.

Looks like there's a bit of coma in the stars at the sides of the image but not huge.

I tweaked it a bit just to subdue the red flaring in the centre and the greenish noise in the background ... hope you don't mind.

:thumbsup:

multiweb
05-05-2009, 09:01 AM
Thanks Steve. Yeah you're right. I'm having a bit of trouble shooting flats with the C11 at the moment. I ordered an A3 EL-sheet. For some reason the 9000ADU level that worked for my 5" overcompensate the flat fielding on the C11. Weird. I have to work out some proper levels of exposure. I think using myA4 EL-sheet doesn't help either :whistle: I also need to rotate the guider so the prism doesn't obstruct the CCD (top right corner) Back to the drawing board :P