View Full Version here: : The Pin Wheel - M83
marc4darkskies
11-05-2008, 11:43 AM
Hi all,
Jase’s recent image of M83 is a tough act to follow – but here goes! Although I’m working with half the aperture he used, I’m pretty pleased with the level of detail I managed to tease out. I was also lucky to have had sub 2 arcsec seeing on the night I gathered the luminance data.
This is an LLsRGB image (120, 30, 90, 90, 90) with the additional 30 minutes of synthetic luminance (Ls) added from the best RGB data. Subs were 15 mins for Lum and 20 mins for RGB, all unbinned. Total usable exposure time was 6.5 hours taken over several nights.
It’s a reasonably deep shot so look for other faint fuzzies in the frame.
Small: http://upload.pbase.com/gailmarc/image/96834475/large (http://upload.pbase.com/gailmarc/image/96834475/large)
Large: http://upload.pbase.com/gailmarc/image/96834475/original (http://upload.pbase.com/gailmarc/image/96834475/original)
Hope you like it.
Cheers, Marcus
strongmanmike
11-05-2008, 11:59 AM
A mighty valiant attempt there Marcus! Taking on Jase's image so soon was very daring indeed :)
If I can make some critique (?) I am confused as to whether the detail in the galaxy is indeed real or instead been influenced by your processing..? At first glance there is certainly what appears to be some fine resolution but on closer inspection it doesn't look natural to me :confuse3:. Did you use deconvolution or perhaps wavelet like proicessing by any chance? Something in your processing has imparted a minimum filter/overdeconvoluted appearence to the finished result..?
The detail in the little companion galaxies is the best I have seen though and does look real.
Great work and long live the APO's :thumbsup:
Mike
A beautiful shot Marcus, I like it a lot.
Paul
Dennis
11-05-2008, 01:07 PM
Hi Marcus
Wow – another feast for our eyes! You have produced a startlingly beautiful portrait of this amazing galaxy. The large version is just gorgeous to scroll around, peeking into all the nooks and crannies.
I really enjoy how clean this image is; there is no noise to take the edge off my viewing pleasure. I am also astonished to see detail in the two smaller galaxies riding below M83. Top stuff.
Not to mention the other galaxies scattered throughout the background – fantastic!
Cheers
Dennis
marc4darkskies
11-05-2008, 01:14 PM
Thanks Mike - critique away mate - no probs at all!! :thumbsup:
Yes, I enhanced the lum selectively with wavelet - the central region mostly to tease out some additional contrast. I normally do some selective wavelet or deconv to the lum - when the data is good. I'm always careful not to add or subract detail though (by referencing images from large scopes) but changing the detail a bit is generally unavoidable if you do any kind of sharpening. You could argue that I overdid it though - I'll have a look when my eyes are fresh - perhaps I'll also post the completely unsharpened version FYI.
I was quite surprised at the detail in the raw (stretched) image ... the smile on my face grew by the minute as I started processing. Definitely a testmanent to good optics (and good seeing).
Thanks for the feedback!
Cheers, Marcus
Peter Ward
11-05-2008, 04:57 PM
Marcus,
I have no meaningful criticisms to make here :)
Dammed fine image!
Peter
renormalised
11-05-2008, 05:16 PM
Another damn fine looking M83!!!. Maybe not quite there with Jase, yet, but not far away from there. You need a bigger scope:D:P:)
Just as a note.....I went cross-eyed trying to count all the fuzzies in that pic!!!:eyepop:
iceman
11-05-2008, 06:15 PM
That's a very fine image, Marcus! Just beautiful.
Excellent resolution and detail.
rmcpb
11-05-2008, 06:49 PM
Marcus,
Its images like that that almost make me go to the dark side BUT imaging is sooooo much work and I'm lazy.
Brilliant
marc4darkskies
11-05-2008, 10:36 PM
Thanks Paul - glad you liked it!
Thanks a lot Dennis! Yes, it's quite a deep image. You should see all the faint fuzzies in the full, uncropped frame! As well as revealing faint detail, the use of longish subs (15 & 20 mins) allowed reduction of noise to near zero without much effort and without damaging detail - especially in the background.
Cheers Peter - I think I'm starting to get the hang of it now ;)
Thanks! Of course, I really can't compete with the >12" RCOS' of the world - but just maybe I might sometimes be able to make the folks using them peddle a bit harder to stay ahead ;) :P
Hmmmm - a bigger scope eh? :confuse3:. Here, let me practice. Hi honey, you know that really expensive telescope I bought only 2 yars ago? Well it's time to buy an even more expensive one! :whistle: <thunk> ... sound of lead brick hitting the ground.
Nah, happy with my 6 inches :D
Cheers, Mike. I'm pretty pleased with it. Not sure whether to be proud or embarrased when I tell you it's the result of nearly a week's work. Don't know how some of the masters knock them out in a couple of hours(?)!! :shrug:
Thanks mate! Yes, it's a lot of work but the power of the dark side is compelling and addictive <sound of heavy breathing behind a plastic helmet>
Cheers, Marcus
montewilson
12-05-2008, 07:14 AM
Cool image - It was good to meet you at the SPSP. Keep up the good work.
Regards
Monte
Hat goes off to you Marcus. Not a bad effort at all. Around the nucleus does appear to be a little too over processed for my liking, but a fine achievement none the less. Well done.
Garyh
12-05-2008, 01:09 PM
Well I can`t pick on it at all...very enjoyable viewing!
I like the colors!
Beautiful Markus!
cheers
marc4darkskies
12-05-2008, 09:45 PM
Likewise Monte and thanks! BTW, I built my first T-Point model! :)
Thanks a lot Jase! :), appreciate that! I had a look and really all I could see that I didn't like was some grainyness around the core. I backed out some sharpening but I doubt you'd notice the difference. Anyway, it's nothing that would be visible in even an A3 enlargement. I also backed out a bit of star size reduction (blasted minimum filter) but again, very subtle.
Hey thanks Gary! Glad you liked it! I'm pretty chuffed with it.:party:
Cheers, Marcus
So you should be chuffed with it Marcus, what a wonderful image !!
The colours a so vivid and you've got gorgeous detail in the spirals.
Keep up the fantastic work mate.
:thumbsup:
Tamtarn
15-05-2008, 08:58 PM
Beautiful image Marcus. It looks spot on as far as balance and detail and the background is very smooth.
Nice job on the background galaxies also
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