Ngc6164-now with full reprocess!

[Bart]

Hi, I hope everyone is safe and well. :)



This image is definitely not my best work although it took some doing to get it to turn out as well as it did. For 15 hrs total (7.5ea), I expected better. I've also trialed some new processing techniques like arcsin stretch and I hate what it does to the stars but it is good at preserving the colour.



The OIII still turned out quite noisy so noise reduction was a bit heavy and the halos around the stars from the OIII filter are driving me crazy, I cannot seem to get rid of them. I've even tried different brands of filters and reversing them in the filter wheel etc.



I hope you find something you like in this image.


https://pbase.com/image/170824530


Reprocessed image can be found here.


https://pbase.com/grahammeyer/image/170865934


Stay safe everyone!:hi:

[Placidus]

The outer lobulated OIII rich nebulosity has come out very well indeed. :thumbsup::thumbsup::thumbsup: Very deep. The inner H-alpha rich nebulosity is burned out. Should be easy to fix.

Many professional scopes produce very pretty haloes around the stars. I Presumably internal reflections. You are in the best company. They are not necessarily from the filters. Could be the CCD window for example. That it shows up most strongly in OIII could be because you have to stretch the OIII the most to get a good image, or it could be to do with surface coatings.

Good work.

[marc4darkskies]

As M&T say, the Ha is a little burned out but it's a very respectable effort! Don't be so hard on yourself! You can't get rid of halos completely so live with them - you'll see them all the time in Pro images.

[multiweb]

Nothing wrong with that one. Cool widefield. :thumbsup::thumbsup::thumbsup:

[Bart]

Thanks guys, appreciate the thoughts and feedback. :)

I must admit I did forget about the central region, if it was M42 I would have been right on it. :rolleyes:

[codemonkey]

Very nice! The halos are a bit of a shame, but there's a lot to like in this images regardless. Well done.

[Bart]

Thanks, Lee, nice of you to take a look! :thumbsup:

[strongmanmike]

The halos are but a minor annoyance Graham, the image is otherwise quite a good result :thumbsup:.. and besides, as others have mentioned, pro scope images often show halos :shrug: you could easily reduce or remove the main ones even manually in PS..?

Mike

[Slawomir]

I like the wide field Graham, so many stars! Thank you for sharing :thumbsup:

[Bart]

Thanks for looking, Mike. I think I can do better with this image and am playing with a reprocess at the moment which will include halo reduction. :thumbsup:



Thanks, Slawomir, nice of you to look in! :)

[Bart]

Reprocess of image. Still had trouble with the halos and still tended to blow out the ends of the inner nebulosity although overall it is a much better image. Still more learning to be done, grasshopper!:)


See link in original post.

[gregbradley]

That's a fine image Graham.

Are you using a flattener or reducer? The halos may be bouncing off them and back off the filter.

Baader and Astrodon came out with Gen 2 filters with antireflection coatings to prevent that. Is your O111 filter gen 1?

O111 and S11 are best done 2x2 binned to reduce noise.

Greg.

[Bart]

Hi Greg, nice of you to take a look. I have tried many things for the halos, I've all but given up. I will try binning next time, thanks. :thumbsup: