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View Full Version here: : NGC 346 in SMC LLRGB repro


kinetic
20-09-2009, 09:14 AM
I have a few nights of data now , unfortunately all with
some sort of flaw.
The Luminosity from the 19th last night was super crisp BUT
on processing I get a flare on every star at 7 o'clock
(I think this is just the camera/filterwheel offaxis slightly)

On the RGB from the 17th I have not enough frames for good
S/N and the seeing was not as good as the 19th.

But I tried a basic LLRGB blend as per the Gendler website and
got this.

Colour is obviously wrong...I think this should be a bluish reflection
neb (http://apod.nasa.gov/apod/ap050118.html) type colour so the saturated pink is a bit offputting.
My previous attempt (http://www.iceinspace.com.au/forum/showthread.php?t=50163) got the blue result but way oversaturated.

This is through stock standard Meade DSI red/green/blue filters
and a Baader IR for the luminosity.

Steve

renormalised
20-09-2009, 09:40 AM
Nice shot Steve....what were the lengths of the subs you shot through each filter??.

kinetic
20-09-2009, 09:48 AM
All 5 sec Carl.....

Steve

renormalised
20-09-2009, 11:16 AM
The DSI's mono chip is more sensitive to the red end of the spectrum I believe, so you may have to increase the length of the subs for blue light to get better blue response.

Octane
11-10-2009, 12:46 AM
Steve,

Great effort.

The elongation isn't as noticeable in the LLRGB as it is in the L frame.

Regards,
Humayun

Paul Haese
12-10-2009, 09:41 AM
Interesting nebula this one. I shot it some time ago. I woinder about your camera being square to the optical path though. At the bottom of the image the stars are round (near perfect) and at the top they are elongated. What focusor are you using? The trouble with all these focusors is that they flex at different times. Even the feather touch I have flexes just a little and that is all that is needed to get elongated stars in one part of the image.

Overall, I like the shot Steve. I think somewhere in between both for colouring. I think there is a strong hint of Ha in part of this nebula.

kinetic
12-10-2009, 11:18 PM
Thanks Paul and Humayun for the kind words.
Paul it's a stock standard GSO 10:1 and I think you may be right
about the flexure.
Only thing is, I think in this case it may have been caused by some
of the later frames being rotated slightly by me bumping the DSI
somehow or it just moving by it's cord fouling on the GEM.
The reason I say this is because several re-align attempts using the
stack work better when I do a align with rotate instead of
just pure align.:shrug:

Steve

Paul Haese
13-10-2009, 09:41 AM
That could be it too I suppose.