Oooohhh - NOW I get it!!

[marc4darkskies (Marcus)]

Now I know why people image Eta ... over and over and over again!!!

Forget about "standard candles" ... 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 ... 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 (Humayun)]

Looks fantastic!

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

H

[multiweb (Marc)]

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 (John)]

Well it certainly lights my fire! LOVE IT!

[marc4darkskies (Marcus)]

Originally Posted by Octane

Looks fantastic!

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

H

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

Originally Posted by 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.

No worries Marc. This IS a work in progress you know . 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!

Originally Posted by asimov

Well it certainly lights my fire! LOVE IT!

Cheers Asi!!

[multiweb (Marc)]

Originally Posted by marc4darkskies

No worries Marc. This IS a work in progress you know . 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!

No worries - looking forward to it.

[jjjnettie (Jeanette)]

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

[marc4darkskies (Marcus)]

Originally Posted by jjjnettie

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

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

[marc4darkskies (Marcus)]

Originally Posted by multiweb

... the dynamic range looks a little flat ...

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 (Richard)]

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

[SkyViking (Rolf)]

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

[strongmanmike (Michael)]

Hi Marcus

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

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.....ahh, if that's ok?..and have it on my desk for marking by 9am..ok?

Mike

[marc4darkskies (Marcus)]

Originally Posted by RickC

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

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!

Originally Posted by SkyViking

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

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

Originally Posted by strongmanmike

Hi Marcus

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

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.....ahh, if that's ok?..and have it on my desk for marking by 9am..ok?

Mike

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!

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 . 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 .

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 (Steve)]

Hi Marcus

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

Cheers

Steve

[strongmanmike (Michael)]

Originally Posted by marc4darkskies

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!

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 . 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 .

Cheers, Marcus

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

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.

[marc4darkskies (Marcus)]

Originally Posted by 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.

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).

Originally Posted by Stevec35

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

Cheers
Steve

Thanks a lot Steve!

Originally Posted by Peter Ward

Looks a bit waxy to me (just kidding)

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

Hehe, cheers Peter.

Originally Posted by strongmanmike

... At 100% res it was pretty obvious you had done something,

Originally Posted by strongmanmike

... Overall it just didn't look natural...however shrunk to 50% the second version looks much better, .

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%! Otherwise the less experienced among us will start to think detail is unnatural.

[strongmanmike (Michael)]

Originally Posted by marc4darkskies

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%! Otherwise the less experienced among us will start to think detail is unnatural.

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

[multiweb (Marc)]

Originally Posted by marc4darkskies

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.

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.