NGC 7293 (The Helix)

[marc4darkskies]

Wow 2 images in 2 months!! ... that's good going for me! Thankyou clouds (for staying away for a few nights), thankyou equipment/PC gremlins (for not coming - mostly) and thankyou to my former employer for making me redundant so I can play with my toys during the weeknights. :) :shrug: :confuse3::scared2:

Anyway, just got done processing my rendition of the Helix. A tough subject for sure. It's quite faint - even with over 11 hours of data (admittedly at F11.7) the low S/N in the fainter bits gave me some processing challenges. I've tried not to make it look too forced but I certainly pushed the envelope - I think I pulled it off (?) ... but will revisit later with fresh eyes.

It's a Ha(+L),Ha(+R),GB shot. The raw RGB image was pretty good so I used the desaturated version of it (synthethic lum) to augment my Lum data.

Small: http://www.pbase.com/gailmarc/image/115368783/large
Large: http://www.pbase.com/gailmarc/image/115368783/original

Hope you like it! Critique always welcome too.

Cheers, Marcus

[Bassnut]

wow, that fair jumps out of the screen Marc, outstanding, and some nice neb extention too.

There is a pretty savage cutoff from outer neb to background tho, although the histogram looks OK.

[CoolhandJo]

Amazing detail. Long exposure time sure paid off.

[strongmanmike]

Excellent effort Marcus, looks awesome and quite dramatic! :eyepop:
No meaningful tweaks necessary as far as I can see..? The dark sky actually looks good IMO (wha tha?? did I say that?? shock horror)

I have fond meories of this baby and yours looks very similar to the one I did a few years back :thumbsup:

Jealous of your new found free time too or what?? :mad2:...:P I'm not that keen on sleeping in my freezing car between image capture sets either :sadeyes:

Mike

[gregbradley]

Impinging image Marcus. Nice catch of the outer nebula.
The long hours pay off, quite dramatic.

I am at my dark site and so far 1 night out of 3 was clear.

I also have a Q extender 1.6X and an adapter to use on with
my Microline. Have to check out how it works if I get some
more sky.

Greg.

[Craig_L]

Very nice Marcus. The largest arm of neb extension I think I've seen.

[marc4darkskies]

Thanks Fred. Yes, the cutoff is severe - I don't like it much either - but the signal for the outer neb is pretty low and stretching it more made it look even more artificial. I'll try a few other tricks to see if I can improve it.



Thanks Paul! It took me 3 nights to gather that much data - it wasn't rising until 19:30ish so I could only start imaging at around 22:00.



Thanks a lot Mike! And yes, dark skies rule! ... and very surprised to hear you say that - you master of the blue sky background you! ;)



Thanks Greg - as you'd know this object needs lots of data at the best of times - and I was operating at F11.7!

I think I average only 5-10% clear moonless nights around here. I got an amazing 4 consecutive clear nights for this shot and I stuffed up the first one with comms probs with the camera (silly me - I added a short 15cm USB extension to the camera USB cable to reach the laptop on a new shelf - my bad - the extra length screwed up the USB timing I think).



Thanks Craig. There are a couple of other shots that show it (see an APOD in 2007, Rob Gendlers version and of course Strongman's version). Like Mike I really went to town on my version and exaggerated it as much as possible.

Cheers, Marcus

[gregbradley]

Thanks Greg - as you'd know this object needs lots of data at the best of times - and I was operating at F11.7!

I think I average only 5-10% clear moonless nights around here.

Cheers, Marcus[/QUOTE]


Yes it is an extremely dim object and not many guide stars for that matter either.

I am moving out your neck of the woods further up in the hills in a few months. Already bought a house. When you say 5-10% clear moonless nights is that over the last few years or the last year or so which has been a bit crap anywhere?

My dark site usually is clear when Sydney is cloudy - 90% of the time but the last year it has been the reverse. The clouds seem to be more on the western side of the Dividing Range.

Greg.

[marc4darkskies]

Hey neighbour!! :) I just meant the current "annus horribilous" we're all having in Sydney. The first 1.5 years I was here it was better.

Are you going up Kurrajong Heights way or Bowen Mountain?

Cheers, Marcus

[multiweb]

Beautiful capture Marcus :thumbsup: Really nice details in the center of the eye.

[telecasterguru]

That is a great image and fantastic stamina.

Frank

[marc4darkskies]

Thanks Marc! I think it would have been even better if the seeing had been better than 3 arcsec! In hindsight I should have imaged at F7.3 and gone deeper for the same exposure!



Thanks a lot frank! Imaging at F11.7 on DSOs needs patience - 3 nights worth in fact! And believe me, losing/thowing away a 30 minute sub or two isn't for wimps either - it's enough to make a grown man cry! :sad:

Cheers, Marcus

[Alchemy]

wow !!! best extension ive seen other than mr hubble. very difficult to do. ive done 5 hrs on this one .... nowhere near that much extension.

i think i will just leave it on the hard drive.

clive

[gregbradley]

Phew, that's good to know. Kurrajong Hts way.

Cheers,

Greg.

[marc4darkskies]

Cheers Clive - appreciate that! I had to push process the faint Ha bits pretty hard though. Even with 30 min subs they were very dim & noisy.

Oh go on ... post it! :)

Cheers, Marcus

[Lester]

That is absolutely Majestic.

Thanks Marcus.

[marc4darkskies]

Thanks a lot Lester - glad you liked it! :)

Cheers, Marcus