NGC 7293 (The Helix)

[marc4darkskies (Marcus)]

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.

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 (Fred)]

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 (Paul)]

Amazing detail. Long exposure time sure paid off.

[strongmanmike (Michael)]

Excellent effort Marcus, looks awesome and quite dramatic!
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

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

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 (Marcus)]

Originally Posted by 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.

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.

Originally Posted by CoolhandJo

Amazing detail. Long exposure time sure paid off.

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.

Originally Posted by strongmanmike

Excellent effort Marcus, looks awesome and quite dramatic!
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

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

Mike

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!

Originally Posted by 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.

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).

Originally Posted by Craig_L

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

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 (Marcus)]

Originally Posted by gregbradley

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.

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 (Marc)]

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

[telecasterguru (Frank)]

That is a great image and fantastic stamina.

Frank

[marc4darkskies (Marcus)]

Originally Posted by multiweb

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

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!

Originally Posted by telecasterguru

That is a great image and fantastic stamina.

Frank

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!

Cheers, Marcus

[Alchemy (Clive)]

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]

Originally Posted by 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

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

Cheers,

Greg.

[marc4darkskies (Marcus)]

Originally Posted by 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

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 (Marcus)]

Originally Posted by Lester

That is absolutely Majestic.

Thanks Marcus.

Thanks a lot Lester - glad you liked it!

Cheers, Marcus