Thread: M83 from ARO
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Old 13-04-2014, 02:23 AM
ericwbenson (Eric)
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Join Date: Sep 2009
Location: Adelaide, Australia
Posts: 209
M83 from ARO

So I finally stopped playing with this data set, here are links to the half resolution, and full resolution images. The telescope used was a Planewave 20" CDK on a Paramount ME with an Apogee U16M camera located at my remote observatory near Arkaroola, S.A. The data was acquired at about the same time as the Arp 244 image so I still had issues with stars out of the field of view causing reflection artifacts. The integration time was not very long (<3hrs for each filter), but since this object is so bright it didn't need too much anyways.

It was processed entirely in MaxIm, except for the deconvolution step which was done with the ancient CCDSharp software. I was quite surprised at how well this image responded to the decon, going from 1.9" raw to ~1.3" FWHM.

The processing steps were:
-calibration using bias, dark and flat
-stacking using sigma clip combine
-flatten background using MaxIm tool and superflats generated from the image itself
-deconvolution for Lum channel
-DDP for each channel separately while keeping s-curve parameters matched
-a little extra gamma stretch on the L channel
-adjust bgd for all frames to the same level (btw this removes unwanted color shifts when combining with a non 1:1:1 RGB ratio)
-LRGB assembly
-color balance tweak (at this point large changes can get one totally lost since you have to mind the black points and the scale simultaneously)
-saturation adjust
-crop edges
-unsharp mask of brighter portion of galactic disk

The attached file here is x4 reduced in size and cropped.

Enjoy,
EB
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