Sh2-129 OU4 The Bat and Squid Nebula . . . a real tough target

[Barry-Wilson]

I started collecting data later than planned due to autumnal weather and the target disappearing behind a garden tree late evening (not very efficient planning ).  However being able to begin image capture at 6:30pm really helps and I could grab 3 or 4 hours before said tree intervened or the cloud crept over the Dart Valley.

This has been a real challenge to process and boy (polite version rather than my anglo saxon preferred expletive) is the Squid Nebula faint :=)!  A dark sky and more data is needed to help better define the Squid outer boundary and provide better contrast: I may tweak more yet.  There are 21 x 1200s of OIII and 15 x 1200s of Ha, captured with my FSQ85 at F3.9 and QSI683, 12 hrs total integration.  I don't possess Stratton however it's ability to remove stars and allow further pushing of the OIII channel may have really helped.  PI has some effective tools to help enhance faint background structure - I had to work hard to control subsequent gradient artefacts.  Achieving a balance between the Ha and OII required a lot of trial and error.  There were many blends and complex masks to help develop the Squid structure and I'm not sure I could replicate my processing if I were forced to repeat the processing .

My eyes are fading now and it's time to put this project down!

Thanks for looking.

 

Edited December 1, 2016 by Barry-Wilson
typo

[Uranium235]

Certainly is a tough one.... bet youre glad to see the back of it!

 

[ollypenrice]

It's a monster of a target, Barry, but you've found a lovely smooth and consistent OIII signal there. I'm afraid that mine shows some scars from the brutality used to make it confess its own existence!

Olly

[laser_jock99]

Great effort.

[toxic]

i can only say awesome image Barry

there are only 2 hopes of me getting anything on that object and its either bob hope or no hope.

[Allinthehead]

Nice. The full size image is amazing.

[PatrickGilliland]

I think this subtle version stands up well.  Something I am still learning is recognising the boundaries of the data you have and working that to its maximum and not beyond.  You seem to have that subtle touch, knowing just when to stop but not before!  Of course more data will help to a degree and a dark site even more so.  Personally I think this is a great effort with what is actually not much Oiii for this target. It works as an overall image, good balance and colour.  Sure you could try to do more but not convinced that data would offer you more.

I suppose i will have to have a go at this - maybe next clear night i will run some test Oiii and see how that goes.

Paddy

[Rodd]

I remember the OIII channel having a huge amount of noise.  Then again, maybe that was me.  This is as good as can be expected from a target not discovered until 2011!

[johnrt]

Great effort Barry on such a difficult target. 

[Stephen Green]

That is a very nice  image

[Barry-Wilson]

Thank you all for the kind words.  It has certainly felt like an effort to process this one.

Firstly I combined the channels when linear and processed but any attempt to push the data to elevate the Squid beyond the background just blew the stars and the strong Ha Bat signal.  It was a shocker to behold.

I then processed the two channels separately to their non-linear stage giving the OIII stack an astounding stretch and background enhance.  After combining the non-linear stacks (with a mildly stretched OIII stack) into the HOO base image, using carefully crafted range masks to isolate the Squid, I could then layer over the HOO the enhanced OIII signal.  Chrominance noise was terrific in the Squid and had to be tamed with carefull application of NR to preserve what little structure there is in the nebula.  Despite the use of PI's HDRWavelets I decided to dispense with this process as I felt the results were too much a product of the algorithm and not a 'real' representation of my data.

22 hours ago, PatrickGilliland said:

I think this subtle version stands up well.  Something I am still learning is recognising the boundaries of the data you have and working that to its maximum and not beyond.  You seem to have that subtle touch, knowing just when to stop but not before!  Of course more data will help to a degree and a dark site even more so.  Personally I think this is a great effort with what is actually not much Oiii for this target. It works as an overall image, good balance and colour.  Sure you could try to do more but not convinced that data would offer you more.

I suppose i will have to have a go at this - maybe next clear night i will run some test Oiii and see how that goes.

Paddy

It is an art to balance one's desire to make the subject of the image shine, but I felt I would push my data too far if I went for a resplendant Squid.  Whilst there are super NB images on the web which aim to highlight the contrast and structure of the two nebula, I wanted to represent what my mind's-eye might imagine you would see through an eyepiece (if such a thing were indeed possible).

What is startling and amazes me whichever image I view, is the variety of colours and forms that PNs take in our wondrous universe.  You've got to love'em!  Just need a really BIG scope to display them at their best .

Thank you all once again.

Edited December 1, 2016 by Barry-Wilson
typo

[ChrisLX200]

How did I miss this? That's a wonderful effort Barry, and I know only too well how tough a target the OIII squid is and you have showing clearly.

ChrisH

[simmo39]

That is a real small flat fish!   BRILL !!!

[Barry-Wilson]

Thanks Chris & simmo39.

[StargeezerTim]

Beautiful image Barry 

[Barry-Wilson]

Cheers Tim.