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swannies1983
25-05-2012, 02:09 PM
I decided to do a repro on my M83 based on comments by Alpal. It was suggested to convert my RGB image into a grayscale image, and process this as a pseudo luminance layer before combining with the RGB data using the luminosity blending mode. The jury is still out as to whether this method is worth the effort. Anyone else do this? While I'm sure it still need a bit of work, I'm happy with the result given this is my first attempt as this processing workflow.

Details
Scope: 8" Newt
Camera: unmodded 400d
Exposures: 19x10mins @ ISO800 (total exposure time of 3hrs 10mins)
Hutech Light Pollution Suppression Filter
Lights, darks and flats stacked in DSS and processed in PS.

Comments/suggestions always welcome :D

Better resolution image here (http://www.flickr.com/photos/47268787@N05/7265659072/in/photostream)

Cosmic
25-05-2012, 10:27 PM
I can tell you now its a nice image to look at. Yes the processing side sometimes ends up longer than the total exposure time haha. Never get sick at looking at m83, great work mate :thumbsup:

h0ughy
25-05-2012, 10:55 PM
looks pretty good - popular target this one ;)

alpal
26-05-2012, 12:52 AM
That's definitely a big improvement.
Look at the old image:
http://www.flickr.com/photos/47268787@N05/7245486966/in/photostream

There is far more detail in the core now .
The 2 , little galaxies at the top stand out better as the
background has obtained more contrast from the noise.
The colours are better showing the red nebulosity of
the nebulas inside M83.
Well done - I knew that data was good.

Rigel003
26-05-2012, 08:29 AM
Dan that is an improvement, especially with respect to the sharpening. There's definitely more fine detail visible. Not sure about the colour treatment though. There's a contrast between the core and the rest but for some reason the capture didn't pick up the colour contrast between the arms which should be blue and the small red clumps of the HII regions. I think your star colours may be a little more washed out in this version too. Maybe a longer capture under dark skies would help here. Nevertheless it's a fine photo and well processed. You should be pleased with this.

swannies1983
26-05-2012, 09:47 AM
Thanks for all the comments guys, especially alpal for the help :thumbsup:

Graeme: Yes, after looking at it again this morning, I'm not happy with the colour balance. This has been a sticking point with a few of my images so far and some of it comes from using a light pollution filter. Once I get the background colour sorted, M83 is pretty much just blue. I had to add the red to the core myself. My camera is unmodded* so I'm not sure how to go about getting the Ha regions in the arms. Darker skies would always be nice but longer exposures saturate the stars. I might have to try shorter exposures and blend the stars through. I have to learn how to do this.

*I now have a modded 30d (thanks Troy) but haven't had a chance to test the camera properly yet.

astronobob
27-05-2012, 11:58 AM
YOHaaah Thats 100% improved Dan, going forward in leaps and bounds :thumbsup: