Anatomy of a Swan - M17

[Dave882]

I've always struggled to see the swan in M17 - but if you can kinda imagine a swan attempting to cross a busy highway and getting mowed down by a b-double... :P

Taken over 3 nights last week during the full moon, the L-Ultimate filter has really proved to produce excellent contrast even in very poor conditions. Initially I attempted processing the Ha/Oiii channels separately and combining in PI, but actually preferred the more natural colour when processed together. The fov from my c14 @ 2670mm was juuuust a little too tight so I expanded the view with a 1.5x1.5 mosaic, and APP processed and combined that perfectly without even having to engage the specific mosaic registration tool.

RGB stars were added also during the full moon using short binned 10sec subs, processed separately in PI and then added to the narrowband image. I'd read that this can still produce acceptable results, and seemed to be ok however the colour is still a little washed out perhaps.

I spent quite a bit of time processing this image to retain detail in the bright core. HDRMT was very useful, and BlurEx used very sparingly here in the final stages, but handy for star reduction and adding some halo-glow to blend the 2 images together.

Here's the larger/much better res version: (https://storage.googleapis.com/dso-browser.com/astrophotography/picture-9377209aeae295cdd9e879964f24fbef-original.jpg)

Image Details:
240x 120sec subs (L-ULtimate Fileter)
400x10sec subs (no filter)
Celestron OAG
C14 non edge @f7 with the Starizona reducer LF
EQ8 pro
Asi2600mc pro gain 100
Asi220mm / celestron OAG
ZWO EAF
ASIAIR pro / APP / PI
Binned (scaled) 50% in processing

Comments and suggestions for improvement very much appreciated!
Thanks for looking.

[strongmanmike]

A fine up close and personal swan there Dave :thumbsup: surprised you struggle to see the bird though :shrug:..I've always thought it was one of the easier monikers to make out :shrug: perhaps resembles a duck a little more when viewed through and eye piece :question: The number of times over the years I've used the "see if you can make out the duck" during outreach observing sessions, is very high :thumbsup: But either way, it does resemble either bird swimming on water.

Mike

[petershah]

Well Dave the struggle was worth it...nailed it!!

[Addos]

really nice Dave! Colours very natural, and nice detail starting to come through!

Only thing I would suggest is to go for longer subs on the dual-band filter so you can saturate the sensor a little more and pick up the fainter stuff around the edges.

[Retrograde]

A very nice close up with some lovely, subtle details.

[Startrek]

Dave,
That’s a lovely M17
That big quality scope with quality accessories shines again
Really good resolution up close
Well done !

Cheers
Martin

[Dave882]

Mike- Thanks yes I really love getting in up close to some of these well known targets - Yeah I guess I can see the head and neck but after that a bit like roadkill to me :lol:

Peter- Thanks mate, yes a few struggles, but aren't there always!! I tell you though, the L-Utimate has almost complete removed one of my biggest hurdles being the bright city LP. Just so much easier processing.

Adam- Thanks for you suggestion, you're right there's definitely more to be revealed out wide although I reckon more hours would be more effective than increasing the sub length as I was only just able to control the core as it was.

Peter- I'm glad you liked it. I did put a lot of effort into retaining the subtle detail through the processing. Especially in the core, it's incredible to see what can be revealed particularly in the bright areas.

Thanks Martin - yes I was really happy with the detail revealed, and although a blue/orange Hubble-esk pallet could increase contrast slightly, or push the decon/BlurEx to sharpen it more, I actually preferred the more natural look and there's quite a bit of natural contrast too.