~158hrs on the Helix Nebula

[joshman]

This image has been such an annoyance capture and process, between some poor data management last year, clouds this year, and some difficult (for me) post processing hurdles, I've managed to put 158 hrs of data into this image.

The Helix Nebula is one of those surprisingly complex Deep Sky Objects. On the surface, it is incredibly easy to shoot - it's large, bright, and fairly easy to get a great image with only a few hours of integration; However a bit more integration time reveals the existence of a quite extensive and very faint outer Ha shell. The near 60hrs of Ha data in my image only just starts to hint at what I believe to be the full extent of this outer shell.

As Always, C&C is very welcome, especially on this image, as I'm not 100% on board with the current processing.

Be sure to check it out on Astrobin! (https://www.astrobin.com/wzgjns/B/)

Thanks for looking, and Clear Skies!

[Nikolas]

Awesome image, I reckon you can get way more out of this with some selective processing as it appears to me the black areas are clipped and you can get way more nebulosity in the fainter areas. Especially with so much acquisition time.

[joshman]

Thanks Nik! You're completely correct! There is a lot of Ha detail being left on the table in that process. I've gone back to the drawing board and reprocessed it to showcase it more prominently. There is a huge amount of Dynamic range in this target, and the faintest details are really close to the background/noise floor.

[Nikolas]

Wow that second image shows so much more!!

[gaseous]

That second photo is bonkers.

[TrevorW]

In all honesty I think 158hrs didn't achieve much more than say 22 hrs posted by another forum member. Statistically, each successive doubling of the number of exposures will increase the signal-to-noise ratio by a factor of 1.4 i.e. the square root of 2. there is a law of diminishing returns since each successive exposure has less and less impact on the final stacked image. The image is nice but no more so than others that have posted with lesser total integration. Sorry but that is my opinion for what its worth :)

[joshman]

Thanks Nik! I definitely think that there is more to be seen hidden in the background with some significant integration time investment.



Thank Patrick!




True... but I'm not chasing more detail in the core, that can be had after just a few hours, I'm really chasing the background detail; the really faint extra shell(s) around the outside, and the 58hrs of Ha in my image is (I suspect) only scratching the surface of what's needed to really show their full extent.


See the attachment for an inverted copy of the Ha Channel to see what I mean.

[strongmanmike]

Love the inverted Halpha, so cool, you have gone pretty deep :thumbsup:

Mike

[Dave882]

This is wonderful mate. What an epic project and congrats on a great image. I love that Ha data. Wow what amazing detail in those outer shells!!

[joshman]

Thanks Mike! It's the deepest Helix I've ever seen. ;)
(that was the goal)



Thanks Dave! I'm really happy with the amount of detail I've been able to bring out in those outer shells. I'm looking forward to adding more in the future.