Eta Carinae Mosaic (Star-less repros added)

[RobF]

Unashamedly inspired by Humayun's epic first light portrait of Eta with his Tak and SBIG gear, and with my lotto tickets yet to deliver, I figured now might be a good time to tackle my first large mosaic. I'd like to say I've put in a bigger secondary, 3" moonlight focuser and bought a 16803 based camera, but this is 8 frames in RGB combined using Pixinsight's wonderful mosaic tools. Its not too hard to spot colour transitions in the background in places, but I didn't want to pike out and just post in mono, and this is the best I've been able to do so far. I managed to botch collection of green and blue filters in the Eta region, and thus had to go back on a different night with the camera ever so slightly turned compared to the original data, so unfortunately the diffraction spikes on Eta Carina are a little out of whack.

Collected over a few nights early in February, then processed nearly every night for the last 3 weeks:

8 frames RGB 15:15:15 (5x3min subs per frame)
(QHY9/QHY filters/8" Newt & MPCC)

[Suzy]

Beautiful pics Rob. :)
But if I may add my 2cents worth :question: ... it would have been fabulous to see one of those pics in the mosaic showing the two beautiful star clusters sitting very close to E.Carinae. Just completes the mosias I think. Anyway, just my thoughts. I love all your work and am one of your biggest fans. :D

[Octane]

I'm at St Leonards train station viewing on my iPhone, but, that looks stirling to me.

If I may, a touch more brightness (perhaps 2/3rds of a stop) and a smidgen contrast would really finish it off.

Fabulous image, Rob. I just love your star colours.

H

[strongmanmike]

Overal it looks pretty good Roberto and well done on the mosaic it looks ok too, you are one up on me there still :thumbsup:...I'm a chicken :scared3:...and I have a busy and heavy portable rig so multiple frame projects over multiple nights are rather unappealing :scared2: :whistle:

Mike

[multiweb]

Well that's beautiful Rob. You did a grand job. :thumbsup:

[spearo]

a lot of work went into that!

I like the framing!
well done
frank

[Stevec35]

The full view looks great Rob and I like the star colours a lot.

Cheers

Steve

[astroron]

Nice work Rob,splendid rendition:thumbsup:
cheers

[RobF]

Thanks for the kind comments everyone. Glad to see you've had a bit of the fun viewing it I did collecting and assembling. I should have said in the 1st post this data was all binnedx2 - another first for me, which required new darks/flats etc but all character building stuff. I went through quite a few phases with this - initial grand plan to cover H's work in 6 frames, followed by the realisation in the cold hard light of day the overlap wouldn't be enough, then after collection 4 frames (and succeeding in getting the red frames to fit) thinking "whatever - I'll just go for it". 6 frames would just about cover this field of view, but I learned a lot about composiing and navigating around mosaic frames along the way. You can get an idea of the number of false starts by looking at uncropped mosaic assembled here:
https://picasaweb.google.com/UserRobF/RecentWork#5580564329431758866




Thanks for having a look and commenting honestly Suzy. I actually agree whole-heartedly. One of the things I love about Humayun's pic is the grand field of view that DOES capture Southern Pleidaes, but also creates great drama by including enough of the darker sky around the neb. I just wasn't game to go to a 3rd column of data though after the adventures I describe above. Maybe one day. If you look carefully at the star spikes on the right hand side versus left they've actually rotated to reflect the curvature of the wide field. It took me 2 weeks to figure out that PixInsight can actually handle this by registering against a master artificially generated starfield. Anyway, thanks for the kudos. Head now returning to normal size :lol:



The wonders of modern Apple gadgets! Thanks for checking it out H. I honestly wouldn't have been patrolling this area in such detail if you hadn't made my chin hit the desk back in early Feb. Thanks re stars - this is the first time I've separately tried to do anything to my stars. I softened them a little using morphology function, boosted sat, then blended that back into the main image so as to not overdo. I've still got lots to learn to get anywhere near the "tak" stars you, Marcus and others make look so damned easy....

Sorry if I keep harping on about your Eta here, but it really did affect me strongly - so just telling the truth.

As for brightness/contrast, I'm way behind your deftness tweaking those final "big picture" settings. I don't think there's any shortcut for taking and tweaking LOTS of pics to get a feel for it. I might revist after I've had a few early nights to top my sleep up again.



Cheers Mike. With my relatively portable rig its pretty easy to plonk it on marked tiles in my backyard. I was able to leave the scope up over 3 nights for most of this which made it easier. I should have collected more data, but same old story for me - I wasn't sure I could make it work, so I wasn't going to spend forever on what was really "proof of concept". I'll happily swap rigs though if you want to be more portable :whistle:



Thanks Marc. Pretty happy chappy with this one



It wouldn't have been chosen so well if Humayun hadn't given a lesson in composition for his is the truth Frank. Wish I could have snuck in the bottom of the neb and IC2602 to boot though. I thought about getting more data, but I'm all mosaic'd out at the moment



Thanks Steve - I was trying to make them nice and rich without overdoing it



Thanks for commenting Ron. I had to make do with staring at a screen last night rather than breathing in fresh air under clear skies :sadeyes:

[peter_4059]

Nice going Rob. Taking a mosaic with RGB takes some dedication.

[ozstronomer]

Rob, stunning work!! That has been a labor of love so may subs, so may frames but the effort has been well worth it :thumbsup:
All three are great but I love the Gabmistral framing.

Cheers Geoff

[RobF]

Probably takes a fair bit of madness too Peter, but I ended up learning a fair bit about collecting and then processing as I expected. I think a 2x2 would be far more manageable next time I feel the inclination, and 1x2 definitely worth checking out for a FOV boost. I love my rig in general, but we Newt drivers can't help lusting for a bit more FOV sometimes.....



Thanks Geoff :)
I honestly didn't realise the GM neb was that close to Eta until H's pic. Its certainly a fascintating object. My first though was just to do that neb and a bit of the nearby Eta nebulosity as per the cropped view possibly even with the Southern Pleidaes in there, I went a bit nuts after that. Still no-where near the FOV of the 11000 though.

[Octane]

Had to have another look, Rob. This is pretty epic.

By the way, I think you're referring to the Gem Cluster, NGC 3293. The Southern Pleiades are a ways out.

H

[RobF]

Oops
Thanks Humayun - I'll have to do a bit more reading on the area obviously....

:thanx:

[jjjnettie]

Rob, how did I miss this??
Too beautiful for words mate.:thumbsup:

[RobF]

Thanks Jeanette. It became quite an obsession this one, but something I've wanted to do for quite a while, so glad to get something pretty decent after all the learning (and swearing :P)

[gregbradley]

Very nice Rob. I appreciate the difficulty of mosaic construction. I am yet to complete a couple I have shot myself.

Greg.

[alan meehan]

:thumbsup:Very nice ROB you have to pleased with that
excellant work pixinsight is such a great tool
AL

[Hagar]

Very nice Rob, a big task putting together a mosaic. You have done this one very well. Can't wait to see what comes from the 16803.

Nice job.

[RobF]

Thanks for that Greg. CDK17 frames mosaic'ed - now that's a scarey but wonderful thought, imagining what that might look like!



It was certainly a learning curve Alan. Thanks goodness for the PI forums though. Juan has kept steadily adding to the mosaic processing functions to the extent I pretty well had to learn them all to figure out what could be used and how. Still - cameras, computers and stars - that's a big reason I'm hooked I suppose :)



Just dry humour on the 16803 Doug - if only the funds really would stretch that far. There's plenty to explore with this rig though, especially now I know I can knit up a few frames if need be.

[h0ughy]

excellent results Rob - done well, only get better from here as you get to know how to process better - Maybe do a repro and avoid some things you did before, its certainly a program where you can trial and error to get something to what you like

[RobF]

Thanks David. There are certainly a few spots I've since found, particular bottom middle, where the colour alignment is off. I suspect I must have manually selected a wrong star pair when doing the final dynamic alignment for R, G and B.

Always something to play with with repros. I'm still a bit "Eta'd out" at the moment though :lol:



Edit: Oooooh - almost forgot - have attached an (almost) starless version too

[RobF]

Sorry - I'll go away soon - promise...
Star "less" version 2 - with a bit more oomph. :whistle:
Trouble is it shows up some of my dodgey processing for flats/background.

[Octane]

Rob,

That's got the hallmarks of another wall-hanging masterpiece.

Two suggestions; flatten the background a bit to black. It doesn't necessarily have to go all the way, just don't let us see the magenta tint. Secondly, just a bit of contrast. I'm the last person to be talking about contrast as I like low contrast images (I make them myself, too), but, this could do with a bit.

An entry for the Malin's.

H

[RobF]

Thanks for the pointers Humayan - greatly appreciated. I might work up the courage to go back a fair way in the processing and flatten the background a bit more. I was worried about pushing too far and ending up "over-processed", but I guess I'm alreaedy heading off into the hills (Fred's hills?) when I start taking out stars.

I was surprised and pleased with the overall effect when I had a play last night with min filter and single iteration of dust/scratches, so thought I'd put it up for reference.

Cheers,
R