M83 - 7.5 Hours

[rat156]

Hi All,

As usual I couldn't resist doing M83 again, it seems each time it comes around I have some new gear to try.

Here's the first go at processing.

LRGB image 4h40mins Luminance in 10 minute subs, 1 hour for each colour in five minute subs binned 2x2. Processed in CCDStack and PS.

Cheers
Stuart

URL for larger image http://tinyurl.com/26rc24v

[CoolhandJo]

Very nice indeed. Pops out at really. Natural colours..

[multiweb]

Great shot. Nicely processed too. :thumbsup:

[marc4darkskies]

Nice one Stuart! :thumbsup: Some nice detail there. Looks like maybe some black clipping going on though?

Cheers, Marcus

[gregbradley]

Very nice Stuart. I like the colours and detail.

Greg.

[lesbehrens]

very nice, love the detail.
les

[TheDecepticon]

Good colour and detail, but does look clipped in the dark zone. Good stars.:)

[jjjnettie]

Beautiful!
I'd love to be able to produce images like this.

[TrevorW]

Nice Stuart maybe a tad clipped, I'd expect more in the spirals for the data collected though

[rat156]

The light pollution removal tool I use (and have to) when I shoot from the 'burbs has a tendency to really knock off the noise in the background, hence the background looks clipped. I'll back it off when I do the second iteration of processing.



Again see above, the joys of shooting stuff like this from Melbourne!



So did I Trevor, but I pushed the data as much as I could without making stuff up. This is probably all I can do from home, I'd need to go to a dark site to get any more of the outer arms. The signal is probably there, it just can't fight through the LP.

Of course there's always the Mac v PC problem I have, as I process on a (calibrated) Apple 30" monitor and a MacPro, sometimes the gamma differences in the PC monitors and video cards make my pics look a bit dark. I don't know why this is, but they look OK on my work PC (also calibrated) and the 27" iMac (running Windows) that I'm using to post this.



Thanks Nettie, and all the other posters as well. If I can do this, anyone can. I'm thinkiing of posting a progressive M83, I reckon I've had at least three goes at it with varying gear. It'd be interesting to see the progression.

Cheers
Stuart

[mental4astro]

Beautiful picture! Lovely details and numerous background galaxies.

One thing I've noticed in this picture is what looks like streaky extensions of the arms, effectively tripling the diameter of M83. These streaks surround the main halo following the follow of the arms. Not a dirty screen as these streaks move with the image as I pan over it.

Part of the galaxy or some type of imaging artifact?

Alex.

[Paul Haese]

Nice image Stuart. I think the star colours could do with some work though. I think they are a little under saturated. I found this galaxy to be quite a hard object to process. Finding that right balance can be tricky. Nice to see an image from you.

[asimov]

Looks good to me, & very thoughtfully processed too. Doesn't look overly clipped on my calibrated monitor.

Top job.

[multiweb]

Well .. it is a little bit clipped. Not much but. I don't think you've lost any details. Certainly not in the dust lanes.

[rat156]

Notice it's mainly in the Green channel, bloody light pollution. I'll post the histogram of the luminance channel, that looks better.

[JD2439975]

Lots of Ha regions showing there & nice detail.
Bit light in the blue & saturation maybe but that's just personal flavouring, I'd be happy with that one Stuart, very nice.

[rat156]

Added reprocessed image, thanks for all the guidance. It's still probably slightly clipped, but I tracked down where it happens, it's when I combine the colour and Luminance images. I use a duplicate of the RGB image as a multiply layer to try to stop the luminance from washing out the resultant LRGB image. This one is darker overall, though the sharp eyed will be able to pick out some streamers from the outer spiral arms (as well as some reflections from dew on the baffles!).

Comments welcome. Larger image at my website (soon).

Cheers
Stuart

[RobF]

Wow & wow!
They're both beautiful, but my fav is the 2nd one - I love the look of those hydrogen cloud "beads" strung along the arms of a galaxy. Dust lanes are resolving beautifully too.

Top stuff Stuart :thumbsup:
You really have that RC singing

[astroron]

Lovely Images,specially the second one:thumbsup:

[Hagar]

Very nice effort Stuart. A very pretty target with lots to keep you processing/ sidonioing for a while yet. I like to see it with a selective saturation lift on the blue blobs in the arms of the galaxy just to top off those little Ha areas. I like version 2 the best.
Well done, lots of work from Melbourne.

[TrevorW]

Second spot on (probably lift luminance and red channel) as per attached (hope you don't mind) but that's just my preference!!!

[rat156]

Play away Trevor, that's the beauty of this stuff, it all comes down to personal preference in a lot of cases.

Cheers
Stuart