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View Full Version here: : Deep sky duo (Omega Cen and NGC 4945)


LightningNZ
16-05-2015, 04:23 PM
NGC 4945 is an edge-on spiral galaxy that appears not far from The Southern Cross (Crux) in the sky, but is actually almost 12M light years (LY) distant from us. It's thought to be a similar size to the Milky Way.

Omega Centauri (NGC 5139) is the largest and brightest globular cluster in the sky. Also seen near to The Southern Cross (Crux) it lies ~15,800 LY from us. Like all globular clusters it is orbiting the centre of the Milky Way. Unlike other globular clusters it exhibits three distinct populations of stars and is now thought to be core of a long lost galaxy, cannibalised millions of years ago by the Milky Way.

Both images have been cropped to ~80% of their original size and comprise 60x 1 minute exposures at ISO 800. I used a 6" F/5 Newtonian reflector and Nikon D5100 camera with a GSO coma corrector and IDAS light pollution filter. Taken on the 14th of May, 2015 just north-west of Canberra.

5ash
16-05-2015, 04:47 PM
Nice colours , like the star field in NGC 4945.What's your opinion on the GSO coma corrector.
Regards philip:thumbsup:

LightningNZ
16-05-2015, 04:55 PM
Cheers 5ash - I said I'd have a go at it. Could have done a little better with the framing in the end but I'm still very happy with it. I got the other little galaxy in there too (NGC 4976).

Regarding the GSO coma corrector - I think it's really good at F/5. Unfortunately the t-adapter is set up for Canon (as can be expected) and since I use a Nikon I still get a little coma in my images. If I'm prepared to crop a little then you don't see much. One day when I win Lotto I'll get a 6D and it'll work perfectly, lol. I presume at the correct spacing it holds up well at F/4 as well. That's what it's marketed as handling.

Cheers,
Cam

cometcatcher
16-05-2015, 10:06 PM
Really nice images Cam!

I don't quite understand about the T adapter. With the appropriate T-ring, shouldn't the spacing from lens to sensor be the same, no matter the brand?

LightningNZ
17-05-2015, 08:18 PM
Good point! I didn't realise the different T-rings are of different depths... Then it really doesn't work well at all. I'm getting ****e results at F/5. Looks totally rubbish compared the results you're getting at F/4 with your MPCC. :mad2: