Narrowband Swan.

[Tandum]

I'm still plugging away at narrowband when the weather permits and I managed to grab a few subs last night and will hopefully get another go on Friday or Saturday night to get some more.

So far this is 8 x 20min S2, 6 x 10min Ha and 6 x 15min O3.

Tak FS-102 @ F8, QHY9 @ -30C and Baader Filters.

Stacked in maxim, processed in CS3 and no flats yet.


[edit]
Changed to a quick Ha,O3,S2 combined image for Carl so it's not green :)
And a really quick S2,O3,Ha with Ha curved back as per richards suggestion, just for a look.
Plus a version following kieths suggested webpage.
I think more data and PS time is on the cards with these filters :thumbsup:

[renormalised]

Nice details, Robin, but it's a bit too green for my liking.

Good shot, though:)

[ptc]

I shot that some time back and got this:
http://www.narrowbandimaging.com/m17_ap180_6303_s2hao3_page.htm

if you want to have it look like that then you need to boost up the Suflur and Oxygen channels and attenuate or at least tone down the Hydrogen

Ha is about 3x to 10x stronger than these other lines so you need to accomodate that in your processing.

I personally don't do sharpening. You can see how that looks in my image.

you have good data but I recommend working the levels and curves to get more full use of the available color gamut.

At the moment you are dominated by Hydrogen

here's an article I wrote on the subject back in August of 2005 that appeared in Sky and Telescope that describes the method I developed for this way back in the late 2001/early 2002 timeframe

http://www.narrowbandimaging.com/tricolor_emission_line_imaging_cris p_page.htm

[Tandum]

Cheers Richard, I have read your document and realise I need more S2,O3 but when you say tone down the Ha do you mean stretch the other 2 more or reduce opacity on the Ha. I'm combining these NB frames using Colour Mapping as Ken Crawford describes in his tutorials. I find selective sharpening can often take the flatness out of an image like this.

[ptc]

I mean both stretch the [SII] and [OIII] more and stretch less the Halpha

one of my operating principles is that you cannot do with photoshop and other software that which you failed to do well in the field. Focus is one such thing. I recommend against sharpening unless you like that overprocessed look.

there are at least two schools of thought: one says there's no filter that should not be used and it is not unusual to see someone spend a week processing 3 hours of data. the other approach is the one I use and that is to use minimal processing. I would spend three hours processing a week's worth of data by comparision.

you can do what you want, but nebulae don't have sharply defined features. the word nebuluous means something that is indistinct and ill-defined and that is descriptive of how the images of them should look from my point of view.

[telemarker]

Some sweet data there Robin. I'm having lots of trials and tribulations processing NB as well (your efforts are orders of magnitude better though). I've been looking around at tutorials and came across this one that describes creating the gold and turquoise hues. Haven't tried it yet but see what you think.

http://bf-astro.com/hubbleP.htm

[Tandum]

Cheers Kieth, I'll have a look. It's crystal clear here this arvo so I'll grab some more tonight. Forecast is more of the same tomorrow night. Eveyone who went to astrofest today should be in for a great couple of nights under the stars at least.

[edit]
Kieth, this is what I get when following that webpage. Also did a quick repo on M16 & M8. Looks like the goods :D