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View Full Version here: : M84, M86 and friends and weird halo


peeb61
23-05-2010, 01:48 PM
Hi All,
Been a while since I posted but here goes.

Image taken during the last period before the new moon, it's a total of over 2 hours worth of:

20 x 7 minute light at 200iso.
20 x 7 minute dark at 200iso
20 x flats at 200iso

Stacked in DSS and processed in CS3 taken prime focus at f/6.3 through my 10 inch LX200 using a modified Canon 350D and autoguided with a Meade DSI.

I have a small problem as you can see from the image, I have this halo in the center, I have included an image of my imaging train.....Any ideas??

Please before I go mad.

Paul

multiweb
23-05-2010, 02:55 PM
Nice shot. Could be a number of things. Coming to mind dew somewhere on one of the glass, slight vignetting - flat fielding not working? In anyway a quick pass of gradient Xterminator should take car of that gradient.

renormalised
23-05-2010, 04:26 PM
Nice shot, Paul. I agree with Marc...could be some reflection off a dew drop or vignetting caused by the Meade focal reducer.

peeb61
23-05-2010, 04:57 PM
Thanks Guys,
Does make sense what you are both saying as the nights have been bad for dew and with the focal reducer buried deep this could explain, maybe I need another heating strap for the reducer.

Interestingly enough one of the faintest I picked out in this field was Mag 18.3 - PGC 169262!

Marc what is this gradient Xterminator??

Paul

multiweb
23-05-2010, 05:04 PM
Russel Croman's Photoshop Plugin (http://www.rc-astro.com/resources/GradientXTerminator/) .

peeb61
23-05-2010, 06:06 PM
Thanks Marc,
I downloaded the trial version and gave that a shot...I think it may have improved it. Such a small price to pay for something that does so much.

Paul