Oooohhh - NOW I get it!!

[marc4darkskies]

Now I know why people image Eta ... over and over and over again!!! :help::D;)

Forget about "standard candles" :P ... there's a lot to see in this giant, extremely bright Neb!!!!

I took this a week or so back and, as always, the clouds and rain have prevented me adding colour :mad2: ... so it's a "rough & ready" WORK IN PROGRESS.

This is an F5.5 image (2.21 arcsec/pixel) but still the detail you can observe in this object is stunning. I used 30 minute Ha subs so I got a massive amount of Ha signal. I added some 5 min Lum subs (1 hours worth) mostly to get some more attractive stellar profiles.

Small:
http://www.pbase.com/gailmarc/image/141866212/large

Large (Full res): Use Cntrl + or - to zoom in and out in your browser
http://www.pbase.com/gailmarc/image/141866212/original

Can't wait to get some colour - fingers crossed for next month!! :)

Cheers, Marcus

[Octane]

Looks fantastic!

I might have to reprocess my 11 hours worth of data from last year. :D

H

[multiweb]

Great details for sure but to my eyes the dynamic range looks a little flat and also a bit over sharpened. Love your work but this one doesn't do it for me.

[asimov]

Well it certainly lights my fire! LOVE IT!

[marc4darkskies]

Thanks Humayun! I wasn't expecting it to be as interesting as it turned out to be!



No worries Marc. This IS a work in progress you know :lol:. The amount of Ha signal I got was huge - all the detail is real! I may reduce the contrast when I do the final processing - we'll see! :) I'm sure I'll change your mind! ;)



Cheers Asi!!

[multiweb]

No worries - looking forward to it. :thumbsup:

[jjjnettie]

:) in the words of Denise Maciel Selmo ..... "My Diva!!!"

[marc4darkskies]

Hi JJ - thanks for that! Hope you're feeling better now! :)

[marc4darkskies]

In the spirit of Marc's comment, I've restored some of the relative luminosity that was absent in the Ha data (but present in the Luminance).

[RickC]

Hi Marcus,
very nice detail in that image, it's good just to get something on the screen considering the weather.
Richard

[SkyViking]

That's indeed a great image with loads of detail. Well done.
Looking forward to the colour version, that'll be spectacular!

[strongmanmike]

Hi Marcus

Wow pretty detailed mate, enough little bits in there to keep a 5 year old busy for hours :eyepop:.

I see what Marc is saying, it does look a little forced at the moment too although the updated version is an improvement, as you say, a work in progress though.

Did you use some multi strength decon on this?

I think as an exercise in seeing how much detail you can pull out it's rather revealing but for the coloured version I would love to see a more natural result..:question:...ahh, if that's ok?..and have it on my desk for marking by 9am..ok? :lol:

Mike

[marc4darkskies]

Thanks Rick and here here - anything's better than nothing!! One of the reasons I chose Eta (almost reluctantly) was because it's so bright I should be able to gather the data very quickly. All I need is another 3 hours to finish it! :prey:



Cheers Rolf - glad you liked it. It will be better when there's some colour though!



Hey Mike - thanks mate! I appreciate the comments and feedback! :) And there's enough detail in there to keep a 50 something person enthralled for 15 minutes! ;):lol:

There was no large effort to render crisp detail. Being such a bright object I had tonnes of Ha signal and the detail was smacking me in the face! Remember also, I'm using a Tak so given the right seeing conditions, sharp images are par for the course :D. At F5.5 especially, crisp images are dead easy to produce - no "forcing" was required!

No decon at all is involved here. Decon and MSDLB in particular should only be applied when you're imaging at small image scales and to mitigate the effects of seeing. In this case, I imaged at 2.21 arcsec per pixel (quite a large image scale) and the seeing was good so most of that seeing was hidden by the image scale. I.e. in these circumstances, when your average FWHM is around 2.5 pixels to start with, there's no point doing decon. In fact, applying it under these circumstances will simply add artefacts to an image and make it looked overcooked. Also, I only apply MSDLB (that by definition produces halo artefacts) to galaxy shots that I shoot at 1 arcsec per pixel. I apply it very sparlingly too - applying it using selective masking - never to a whole frame.

In this image I've applied iterative high pass filtering to the whole frame to increase contrast and make the detail pop. Only about 33% of that was applied. This is the only "sharpening" that's been done. BTW, the trick with iterative high passing is to select your pixel radii correctly - eg too small and you risk overdoing the contrast in the small scale structure. As to the "natural" look, well, that's way to subjective for me, but I will be reviewing the overall contrast of the image when I add the colour. Right now though it looks fine to me :shrug:.

Cheers, Marcus

[gregbradley]

Very nice Marcus. It should be a beauty when its complete.

A cool project would be to extend your focal length and do some short exposures of Eta Carina the star and try to get the homonoculous (spelling?) nebula to show. It may require the Ha to tone it down enough to have it show through the brightness.

Then you could layer it in your widefield. Now that would be cool.

Greg.

[Stevec35]

Hi Marcus

You certainly have the basis of an absolutely stunning Eta there. I'll look forward to the final result.

Cheers

Steve

[strongmanmike]

Ahhh the high pass iterative approach I see, that makes sense actually.

At 100% res it was pretty obvious you had done something, I wasn't sure it was the decon layering technique but had to ask... I didn't think of the good'ol high pass filter. Overall it just didn't look natural...however shrunk to 50% the second version looks much better, although the dynamic range is definitely flattened a tad.

Of course you also must remember, I have been staring at this area of sky on my screen for over a week now too, so my minds eye is a little influenced :screwy:

It's looking great Marcus, great field of view, I'm just musing over the details. I admire your work so much that when I see something I am not expecting I probably just notice it more than anyone else, besides when you post at 100%, as you say, we notice warts and all ;)

Bring on the colour

Mike

[Peter Ward]

Looks a bit waxy to me :) (just kidding)

Way to go Marcus! The Taka is clearly humming on this one.:thumbsup::thumbsup:

[marc4darkskies]

Cheers Greg! Yes, can't wait to add the colour. To do justice to the Homunculus though I think I'd need more than 1760mm (my F11.7 setup).



Thanks a lot Steve!



Hehe, cheers Peter.





Mike ... maaaaaate - of course I'm gonna do something! And BTW, in case I haven't said this before, all serious imagers should post at 100%! :D Otherwise the less experienced among us will start to think detail is unnatural.:lol:

[strongmanmike]

Long live the full res image, long live Marcus Aurelius! :lol:

:thumbsup:

[multiweb]

ah... that's what it is then. This usually enhances the edges of contrasty features and makes them pop. I've used it a lot in the past on shots with a poor image scale but I have found that when the data is quality data it is actually more destructive than anything else especially in the smaller details. It creates artefacts on bright or dark edges and gives this kind of 'bubbly'/embossed look. Have a look at the latest shot Peter Ward posted. It's a very similar image scale (on display resolution) so it's easy to map fine details one on one. Your shot shows all the faint features he's picked in his but your edges are rougher. So I think not sharpening your shot at all with more data will be well on par with Peter's although you guys are using very different instruments.

[Peter Ward]

I see your Schwartz is as big as mine. Soo.. Let's see how well you handle it! :fight:

(sorry..I couldn't resist...plus this would make no sense to anyone who has not seen "Spaceballs" :) )

[marc4darkskies]

Bad precedent Marc - let's just appreciate images that are posted here on their merits rather than compare them to one another - can of worms mate, trust me!! And you don't need to justify your initial position - you already said you don't like it (and I'm perfectly fine with that) - leave it there and wait for me to complete the image. Finally, high pass is not destructive if - like any other sharpening / contrast enhancing method - it's handled properly.


I hate it when my Schwartz gets twisted!!

I'm afraid it's no contest contest Peter - I processed mine blindfolded!

[Peter Ward]

OK you win... I just do plain yoghurt.

[multiweb]

Too much testosterone with your toys guys. :lol: Take it easy Marcus.

[Ross G]

A great photo Marcus.

Smooth and a huge tonal range.

Thanks.

Ross.

[marc4darkskies]

Thanks Ross! I confess I've been a little dismissive of Eta over the years, mostly because it's been done to death. But having seen the wall to wall features and detail present (rarely seen in scaled down versions) I'm now a convert. I promise to do only one version though! :lol:

[strongmanmike]

Ok wise guy, you have'in a go? :confuse3: :innocent:

:lol:

[marc4darkskies]

:innocent: Nooooo ... of cooourse not!! :wink2: ...........

Your repros are one of the reasons we love you Mike! :)

[strongmanmike]

:lol: :ashamed:...I have had a couple of one hit wonders though, while I did do a cropped version (doesn't count as a repro), the Fighting Dragons of Ara was a once only processing result :D...couple more but hmm? not to many others I have to say :question:...seems I am an eager posting Beaver :)

[gregbradley]

I have adopted the policy of leaving an image overnight before I post it and I often find the next day I no longer like the result I got.

You can get too into an image and lose perspective.

i find a bit of withdraw helps. Do something else for a while and come back to it rather than working on it continuously and you see it with a fresh view.

I believe Marcus does that too.

Greg.

[strongmanmike]

Yeh, yeh but that's boring, I like sharing the experience rather than making sure it's peeeeerfect every time before I post, share the experience & love, warts and all, as it were :question: :P

[gregbradley]

Horses for courses. I'd say you're doing pretty well at it!

Greg.

[marc4darkskies]

Does too! :P



Yes I do. It's just that after you've stared at an image for so long the defects and the big picture can become invisible. If not that, then a fresh eye can often spot other ways to optimise an image.



It's not really a search for perfection, although my wife tells me I obsess sometimes. :shrug::help: It's about getting it to the sweet spot where you believe there's nothing more that can be done to improve it. Posting an intermediate step like I did here is sharing the journey and I think that's good, even though some may be tempted to critique it as though it was a final! :shrug: When I do my final colour version I will obsesss, I promise! :D