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Placidus
15-02-2015, 03:54 PM
This Swan is from a couple years ago, with the old STL-11000M. I've reprocessed it knowing what I've learned in the interim.

Even back then, it was a quickie: 2hrs each SII (red), H-alpha (green), OIII (blue). There is a far deeper shot on APOD.

The biggest change in my approach is that I'm pushing the SII much more now, to try to show not how much SII there is (very little, so a green image), but where the SII is (so a more balanced image).

So what does the SII tell us? Every astro-photo is not just a pretty face, it is a story.

Notice the huge arc of red-orange-yellow SII arching up and around the top left of the image, starting perhaps somewhere around 8 o'clock, and finishing around 1 o'clock. For this web of material to be showing in SII, it has to be very thin, cool, material, dredged up from the hearts of probably now dead stars. The webbing suggests multiple tangled shock fronts, perhaps from old supernova explosions.

By comparison, the bottom right part of the image contains almost no SII, and shows much more green H-alpha. This green is code for thicker, hotter, and/or less recycled material.

Hugely pushing the SII (so that you can see this rare and valuable stuff) makes magenta haloes around stars. I've controlled the ones around the brighter stars, but as Bob Marley said, they are just a part of it. I've not tried to eliminate them completely.

Big one here. About 1MB. (http://www.mikeberthonjones.smugmug.com/Category/Star-Forming-Regions/i-QGc77Nq/0/O/0082%20Swan%20Ha%202%20OIII%202%20S II%202hrs.jpg)

Every picture tells a story, baby.

multiweb
15-02-2015, 04:02 PM
Superb! :thumbsup::thumbsup::thumbsup:

RickS
15-02-2015, 05:17 PM
Is the image missing an ICC colour profile, Mike? I think Smugmug mostly handles them correctly so I assume it's the image file rather than the gallery software.

I was going to say I love the colours but I'm not sure if I'm seeing them correctly :)

I enjoyed the commentary as well.

Cheers,
Rick.

DJT
15-02-2015, 06:53 PM
Great image, MnT. I also really liked the explanation, it provides a nice context with the mapping you have selected.

Top job:thumbsup:

alpal
15-02-2015, 08:11 PM
Hi Mike,
another superb result from the 20 inch PlaneWave.
3.5 meters of focal length really gives a superb closeup with lots of detail.

cheers
Allan

tilbrook@rbe.ne
15-02-2015, 08:15 PM
Great work Mike!:thumbsup:

Stunning detail.:eyepop:

Cheers,

Justin.

Rod771
15-02-2015, 09:09 PM
Great image! Love the explanations , very enjoyable. :thumbsup:

geolindon
15-02-2015, 10:17 PM
g day Mike,

i add my thanks for posting another great capture and for the explanations.

i was surprised (i am but a novice) to see the very square edge to the dust in the swan's throat, and other softer squares around its head and at its up-swept tail. so far when i have observed the throat seems smoothly curved.

the squareness reminded of an article "Spider Webs in Space" by Robert Zimmerman in AS&T January 2015 with particular reference to the Red Rectangle, but i dunno if the connection is a valid one.

cheers, L

Placidus
16-02-2015, 06:21 AM
Thanks, Marc. Glad you like it.



Hi, Rick, I've written to you separately asking for a bit of a tutorial on ICC profiles. I know how to embed one, but not how it relates to my particular situation.

Placidus
16-02-2015, 09:32 AM
Thanks, David.



Cheers, Allan, glad you like it.



Yippee ! Thanks, Justin.



Thanks, Rod.

Best,
Mike and Trish (without whose co-pilotage I would take 6 hours of faultlessly guided darks)

Placidus
16-02-2015, 09:47 AM
Thanks, Lyndon.

The very square edges are an optical illusion (but very visible: See the Colombari et al shot on APOD (http://apod.nasa.gov/apod/ap140527.html)

I think the mechanism in the case of the Swan (as Lesa Moore reminded me only recently in another context) is that two sets of parallel shock fronts, at different distances to us, are overlapping on the same line of sight. One set is by luck and history at 90 degrees to the other set.

Best,
Mike

strongmanmike
16-02-2015, 11:08 AM
Wha tha? not another nice colour palette from MBJ :eyepop: ...you are starting to make a habit of this now :D

Your recent software tweaks seem to be working nicely too and the decon is hardly noticeable ;)

This bird looks really cool in full narrowband too :thumbsup:

Mike

Andy01
16-02-2015, 12:25 PM
That's an awesome and intriguing result, well done!
BTW have you considered replacing the NB stars with RGB?

Might be just me but I think it gives an aesthetically pleasing result.

cheers

Andy

Paul Haese
16-02-2015, 02:41 PM
Cool detail and colouring Mike. Well done.

marc4darkskies
16-02-2015, 10:21 PM
You nailed it Mike & Trish! :thumbsup:

Ross G
17-02-2015, 05:45 AM
A great looking photo Mike.

Well composed with excellent detail.

So sharp.

An interesting story, well illustrated by the colours!

Ross.

Placidus
17-02-2015, 07:07 AM
Thanks so much to all three of you. You are generous mentors.

Best,
Mike and Trish

Placidus
17-02-2015, 07:26 AM
Thanks, Andy. Our experiments in RGB stars are in their infancy. Can look very nice, but not sure it's the way I want to go. The other approach is to convert the stars to white. Either way, my self-written star-finder algorithm needs work, to find the faintest ones accurately against nebulosity. Something soon.



Cheers, Ross. Pleased that you like it.

Bassnut
17-02-2015, 07:15 PM
Excellent Guys, as DJT says, your explanations are always informative and add spice to the viewing experience. Its interesting to see variations on the colour palletes you present and why you do.