IC1396 Mosaic update - (Ha(G)OIII) work in progress... (for a long while yet!)

[AndyUK]

Well, I managed to get out and capture another 2 OIII panes this week, so here's an update - To recap, the Ha is 12 panes (51.5hrs in 900s subs) and the 3 OIII panes so far has added a further 14 hours (1200s subs). I must say, it's a LOT simpler framing using the Ha panes to plate solve against

I'm personally not a great fan of HOO images (well, that is I'm not able to process them very well!), but I sometimes find that using Noel's "synthetic green channel" action sometimes produces a semi-pleasing result on some nebula, so just to ensure that things are still heading the right way I thought I'd see how it was coming along...

I must admit, I'm fairly pleased with it so far, but with the nights now getting shorter, I'm beginning to realise that I'll very shortly have to spend 2 nights on each OIII pane and I'm therefore wondering if I'll even be able to finish the OIII this year - I didn't really want this to become a 3 year project, but I guess it's a bit late for that now... I wish I'd picked a smaller nebula now! .

[Fay]

That looks superb Andy. using the great little camera Atik 314L+ as well

Fay

[swag72]

That really is coming along very well Andy - What you need is a camera with a bigger chip!!!

[martin_h]

Mug. Dedicated astro imager... Keep em coming - it's getting there.

[Gina]

Very nice job

[billhinge]

Amazing - well done!

[Mr Bergman]

Impressive!

[RikM]

That's a super image Andy

[ultranova]

Thats looking very nice indeed,

Your nearly there Andy ,dont give up now

[Freddie]

Looking great there Andy. Hope you get the weather needed to complete in a reasonable timeframe.

[prokyon]

Great project!

[Epicycle]

Fabulous mosaic, even incomplete!

[Coco]

Awesome!

[AndyUK]

Cheers all... and yes, I definitely need a bigger chipped camera...!

After starting pane 4 tonight (with the Garnet star), I can now begin to see how weak the OIII channel really is. Unfortunately I only got 10 exposures tonight as it was cloud-interrupted - I'm going to need to get at least another 4 or 5 on this pane alone (and may even have to consider doubling up on OIII for all ). The forecast is indicating Wednesday night might be clear, so I can hopefully top it up a bit then...

[ollypenrice]

Bravo Andy. The colour is coming out very close to RGB. This is not only big and heroic but beautifully processed, smooth and detailed.

If you'd like some RGB for the stars I might shortly have some in stock, Sir!

Olly

[sloz1664]

That is truly wonderful. It may take 3 years but what a delight it will be when it is finished.

I'd like to have a go at mosaics one day, but that big :eek:

Have a word with Sara, she may lend you her beloved 460EX. :grin:

cheers

Steve

[steppenwolf]

I continue to watch this project progress in some awe as it really is an outstanding piece of work, Andy. I admire your tenacity yet wonder where the heck you are getting the clear spells from! Your post-processing is working out just fine so you should be very pleased with your efforts. I for one cannot wait to see the final composite!

[MartinB]

Fantastic work Andy. The Ha looks spot on but the OIII isn't doing anything at the moment. I don't think there is a great amount of detail in OIII which isn't also present in Ha for this nebula so I think you are going to be using it primarily for colour. You will need to give a huge boost to OIII which will bloat your OIII stars and this will then bring you into the dark arts of NB processing. There are techniques out there of manipulating stars, managing colour and controlling noise. You should be getting enough OIII if you are just using for the colour panel

Here's a link to an article on tone mapping - http://cedic.at/arc/c11/sess/CEDIC11_JukkaMetsavainio.pdf This allows you to create non bloated but colourless stars from the luminence channel. If you have a craving for coloured stars you will need to do RGB as well

[michael.h.f.wilkinson]

Lovely project. The result is looking really impressive.

[AndyUK]

Thanks again all !

Olly - One of things I like about this mapping is it's proximity to a "true colour" type output... Whilst it's very kind of you to complement the processing, I strongly suspect that the resolution of having so many panes is hiding all my sins, but I would LOVE to be able to colour the stars in with some RGB, although I'd then need to tap you up on how to apply it! I'd love to try though (if you don't mind)... . I'm sure you can capture your own Ha with that 106/11000 combo ( ), but if you could make any use of this, you're quite welcome to it...!

A 460 would have been a far better prospect for this (if anyone else were considering doing one of these ). I could have captured a very similar field in just 4 panes, so I might well have finished this completely by now!

Steve - To be honest, I'm amazed at the number of clear(ish) skies we've had in the SW over the last 6 weeks, but I suspect that the seeing/transparency has been less than ideal for many of them, as at 1:1 it does look a bit noisy... but again, I'm sure the resolution of having so many panes rescued me a lot with the Ha, but, as Martin's inferred, I don't think I'm going to be so fortunate with the OIII...

Martin - I've looked SO many times at J-PM's website and I've even tried to understand / do that tone mapping but not been that successful... It seems to me that the trick is getting the stars removed effectively without leaving any holes or smudges. I did have a go at removing stars on the Ha, and it actually came out fairly well (again, probably due to the resolution) so maybe it might work this time. If I'm reading it correctly, the untouched Ha is more or less used as a luminance channel, with the stars being removed from the SII/OIII/Ha which are then stretched to the nth degree and then denoised(?). It's obviously all within that link, and if I could get an output as in J-PM's example, I'd be EXTREMELY happy... In fact, I might retire whilst I was ahead . I can see that even if/when I finally get all the data capture out of the way (possibly using Olly's borrowed RGB), processing it to any level of satisfaction is probably going to keep me going for months...

[martin_h]

Here is a star removing action from the astro anarchy web site...you will still have to tweek it a bit after the action but it does work...

http://www.astroanar...abel/PS-actions

In his tone map method a normal Ha is used with a percentage of starless OIII and SII mixed in so that the Ha doesn't dominate the Lum and the Red channel( if you have Ha mapped to red).

[martin_h]

[martin_h]

[martin_h]

[MartinB]

What ever star removal tool you use you will still have some work to do clearing up star residues and it can be tedious!