Finally, three important events collided; clear Brisbane skies, equipment that behaved itself and an operator infused with motivation after months and months spent languishing in the astronomy doldrums.
Tak Mewlon 180 F12 with ST2000XM and CFW9.
Lum = 12x5 minutes.
RGB = 3x5 minutes each.
Brisbane, 11th February 2011.
Flats, Darks, Align, Stack, LRGB combine in CCDStack.
Finished in CS5 (cropped and downsized).
With the relatively long subs for this bright region, the data looks like more could be squeezed out of it, but for the time being, it represents the best I can do with my current tool set and processing capabilities. Love those 3 vane Mewlon spiders!
Thanks for looking!
Cheers
Dennis
Last edited by Dennis; 15-02-2011 at 10:03 PM.
Reason: Reprocessed image added at Msg #14
Thank you Marc, Darren, Louie, Dr Paul, Marcus, Peter, David, Paul & Jeanette, I appreciate your messages.
The stars away from the centre of the field show some coma, a classical effect of the Dall-Kirkham design of the Mewlon. On the few occasions when I look through the Mewlon with an eyepiece, I am usually so overwhelmed by the tight stars in the centre that my mind subconsciously ignores the comatic stars at the edge. However, the larger chip on the ST2000XM records these as dashes, so there is no way of getting away from this characteristic of the Mewlons when using larger ccds.
Thanks Dave and Alex, I've enjoyed everything about this image; my re-acquaintance with the skies and my gear along with the acquisition of the sub frames as well as the processing.
I’ve just added another 30 minutes of Lum data (6x5min subs) from earlier in the same evening and it has made the overall image a little smoother, albeit subtly. This is also a slightly different crop to the original.
Wow, you got a lot of detail in there. The fickle finger is particularly well defined and is a good judge of super sharp optics and good focus.
Greg.
Thanks Greg – I appreciate your comments. If only I had heeded your advice in another Eta post (by 1Ponders) regarding long focal length off axis auto guiding. I spent a futile 12 months or so trying to chase down differential flexure!
I know that some have been successful, but in my case, it seems that only self guiding via the ST2000XM has tamed the auto guiding gremlins that have plagued me with my side by side set up.
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