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Final NGC6888 narrowband

Uranium235

By Uranium235
in Imaging - Deep Sky

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Uranium235

Uranium235

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Just finished this one last night, its an addition to the one I did with the ED80 a week ago. Except this time ive topped up the data using the 150P in an effort to make more use of the limited darkness available.

This time round ive really nailed the blue stuff, which was a little less defined in my last effort. The processing was fun though, trying various ways of producing the RGB image (Stretching before merging or merge then stretch). Ive been reading the curves tutorial by MartinB and its fantastic! The amount of really faint stuff ive pulled out using his curves was quite a shock :)

Anyways, here it is:

NGC6888 Crescent Nebula

Ha/OIII filters

ED80 + 150P, Atik 314L+, 50mm finderguider

Setpoint -10

Thanks for looking! :)

attachment.php?attachmentid=60074&stc=1&d=1307131186

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Uranium235

Uranium235

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Cheers Nadeem, im glad to me moving on from this one now though because I must have processed it at least 10 times before i was reasonably satisfied :) honestly, ive spent more time faffing with the data than actually collecting it!

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Uranium235

Uranium235

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wow you have grabbed that rarely seen outer shell nicely...you must be very pleased

Cheers Peter!

Pretty chuffed :) though I would have liked a bit more sharpness/contrast, which is something I feel im not going to get with data from a bog standard 6" newt.

Saving my dosh at the moment for a 90 or 100mm APO, or im waiting until the 8" SW Quattro carbon fibre f4 newt becomes available (whenever that is!). All depends on the weight really, as 5kg is the limit I set for the OTA weight on the CG5.

Anyways, im gearing up to have a go at the Veil tonight. With the 0.85 FR I should just about be able to fit it all in one frame.

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Uranium235

Uranium235

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Cheers Andy :( I only found out about that shell a couple of weeks ago when looking at some pics I found of it on google. I wasnt even sure if I had the gear to pick it up. I think you should turn your MN190 on this if you manage to get an OIII filter, can only imagine what the result would look like!

Still got an "Astro hangover" here though :) pounding headache, aching limbs..... ahhh we love it really!

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AndyUK

AndyUK

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Well, yes, at it happens I DO have an OIII filter (arrived on Wedneday, with an SII in the post :)). I'm not sure I'd do this justice at the moment though as I'm having a few teething problems (not with the kit but with myself :(). Still, it's in the right part of the sky for me to have a go, so I'll see if I can have a crack at it next time...

I know what you mean about an Astro hangover - Two nights on the trot and having to do the day job as well (and walk the dog for 3 hours/day) does tend to take it out of you... Not that I'm complaining mind!

(Oh, Did you stretch before merge, or merge before stretch?)

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Uranium235

Uranium235

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It was a bit of a complex operation because first I had to merge 2 sets of data (from the ED80 and 150P) before I started. But once I had the master Ha and O3 subs I did a couple of basic curves and levels before merging then saving the RGB master off as a 16bit TIFF that could be loaded into photoshop for some proper curves, levels, NR and sharpening.

I had to do a couple of basic curves becuase the max pixel value at 16bit with a tiff file is 65000, and the FITS format was a bit over that. I do have FITS liberator, but for the life of me i cant figure how to get it to import a colour FITS file. :)

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AndyUK

AndyUK

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Cheers Uranium - I've found myself doing some very basic levels / curves in Maxim first too (before aligning), but had no real idea if it was the right thing to do... I didn't realise that FITS liberator didn't open colour FITS files though - I'll have to have a look at that (although I currently always save to a TIF - Is there any advantage to saving as FITS?).

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Uranium235

Uranium235

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Andy, just cracked how to get FITS colour into PS. First I just did the RGB merge in Maxim - then split the RGB image into its separate colour panes, saved them off as individual FITS files, then badda bing!... They load into PS where I can merge them with Noels actions :)

Just done this with the Veil i got last night, just about to post it :(

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Ant

Ant

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Very nice, it really is a fantastic time of year for Narrowband.

That's a cracker mate and the good thing is that you can continue to add to it.

You must be very happy with the result - how did you merge the images from the different scopes?

Cheers

Ant

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Uranium235

Uranium235

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how did you merge the images from the different scopes?

No problem Ant,

First I tried it with maxim, but it wasnt quite right so I put it though Registar which made a much better fist of it.

I had the option of going either way (matching the ED80 with 150P or vice versa), and so chose to go with the image scale that the 150P offered which meant blowing up the ED80 master frames to fit. I lost a little bit of fine contrast, but that was to be expected.

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lukebl

lukebl

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That's a really cracking image.

Am I right in thinking that you only used H-a and O-III filters (i.e. No RGB)?

It's just that I was thinking of getting an O-III filter anyway for visual observing of the Veil and other nebulae, but hadn't considered using it for imaging too.

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Uranium235

Uranium235

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That's a really cracking image.

Am I right in thinking that you only used H-a and O-III filters (i.e. No RGB)?

It's just that I was thinking of getting an O-III filter anyway for visual observing of the Veil and other nebulae, but hadn't considered using it for imaging too.

Cheers Luke, it was just Ha and O3. I didnt post the exposure details at the time becuase it was PITA to type it all out...lol. But ive just totted up the totals and it was:

Ha 225min

OIII 235min

Combining just Ha and OII is a great way of quickly getting a close(ish) approximation of colour since OIII is a sort of teal colour, halfway between green and blue, which means it can be used for your G and B channels. Im still thinking whether to get an SII, but that would just extend the time I need to spend on a target, which isnt ideal at this time of year :)

But I would definitely recommend it for imaging if you want to add colour quickly. You dont even need the same amount of OIII as Ha because you could do a Ha/Ha/OIII/OIII (L180:R120:G120:B120) combination.

Thanks to everyone for the positive comments on this one, I didnt realise it was still going! Mind you, Ive not really touched the PC much this evening as Ive been in bed having a relapse of man-flu. Couldnt go out now even if it was clear :(

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