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View Full Version here: : Ngc104 - Reprocess (or flogging a dead horse)

DavidTrap
06-06-2012, 09:32 PM
Something a bit out of season,

I was going through my images directory recently and "discovered" some data that I hadn't previously processed :screwy:

I took this last year, a fairly short run of 30 & 60sec subs for luminence and 30sec RBG subs. Using some newly acquired skills in PI, I did an HDR combine the luminence subs, and then an LRGB combine on all of that.

There was a final fiddle or two in PS, but 95% of the processing was done in PI.

C&C welcome

DT

Link (http://users.tpg.com.au/dctrap/astrophotos/NGC104_LRGB_med.jpg) to reprocessed image
RickS
06-06-2012, 10:15 PM
Looks good, David. Nicely resolved.

Cheers,
Rick.
DavidTrap
07-06-2012, 10:32 AM
Thanks Rick,

Need to have a go at deconvolution, but that looks like a whole world of pain!

DT
RickS
07-06-2012, 11:43 AM
I put it off for a long time too, David, but it wasn't so bad when I finally decided to tackle it.
TrevorW
07-06-2012, 01:03 PM
Has the full frame image been cropped

also a little bit of background noise

not a bad Tuc
DavidTrap
07-06-2012, 02:23 PM
Slight crop Trevor,

There was a line of "bad pixels" that didn't get sorted out in calibration that was visible below the left hand small globular on the full size image. I know what to do to fix it.

Any suggestions for noise reduction?

Ta

DT
RickS
07-06-2012, 02:39 PM
Luminance mask and ATWT :thumbsup:
DavidTrap
07-06-2012, 03:13 PM
Ta Rick.

DT
naskies
07-06-2012, 10:17 PM
Nice work. It looks like you're getting the hang of PI? By the way - is that a bit field curvature I see in your full size version?
DavidTrap
07-06-2012, 11:05 PM
Thanks Dave,

I grasp the concepts of PI intermittently!

Yes - some field curvature, usually evident towards the bottom left of the frame. It does show up in CCD Inspector. Probably a bit of slop in the focuser - need to have a fiddle sometime.

DT
DavidTrap
08-06-2012, 12:33 AM
Did a reprocess - see first post for a new link.

Didn't tone down the core as much this time, but have fixed the row of bad pixels and made some attempt to reduce the noise, probably at the expense of clipping the black point.

I should really stop flogging this poor horse - it's only 15mins of luminance data!

DT