Carina Nebula (no longer Eta)

[Atmos]

I don't feel I can any longer call this the Eta Carina Nebula considering I was playing around with the StarXTerminator plugin for PixInsight. Been 5 years since I last did a system update as MacOS 10.15 no longer supported 32-bit software and I didn't want to break a few programs I used a lot.

Saturday night I took the plunge and it didn't break too much but it did open up to a myriad of updates for PixInsight as it's required a newer operating system for some 18 months now.

Had a relook at some old data that had some reasonable seeing in the past, 4 hours of data at 1.6" seeing with the trusty and easy ASI094. Sometimes miss the ease of OSC cameras.

I found that StarXTerminator does a better job at star removal than StarNet ever did. I could do a better job than StarNet the old fashioned way (making star masks) but it would take SIGNIFICANTLY longer. So much so that I didn't bother a good chunk of the time. StarXTerminator beats my best work at star removal, especially on the bigger and brighter stars. It does a better job at separating stars from nebulosity and removes them cleaner.

Also gave BlurXTerminator a go while I was at it, did it before removing the stars obviously. Damn it easy! I'd say the results are fairly on par with what I could do running 100 iterations of deconvolution but the real win is how it separates stars from nebulosity. Heavy deconvolution required a very good star mask to protect the stars from panda eyes. It's almost too easy now :lol:

Carina Nebula Full Resolution (https://cdn.astrobin.com/images/57732/2023/09d8e357-120e-41ee-8a51-37d22ba9d04c.jpg)

Apart from a very slight dynamic range compression using PixelMath, this has just had a basic stretch and saturation after hitting it with some new fancy tools.

[strongmanmike]

Well, Colin, that looks raaaather sharp! :thumbsup:

While it does have a bit of a filter induced "look" (perhaps at least partly due to the star removal, not sure?), it never the less certainly looks to be some great res there. Do you have the "before" shots, to illustrate the changes/improvements these new fancy tools have made to your original efforts? love to see them :thumbsup:

What scope was this again and what image scale were you shooting at?

Mike

[Atmos]

It at least doesn’t have the look that Topaz sharpening AI tool did, it worked pretty well on terriestrial images but it damaged stars pretty bad and created structures that didn’t exist. I did some testing with an image of Omega Cent last night to see how it dealt with a purely starry image and it’s pretty impressive.

This is my last attempt (https://cdn.astrobin.com/images/57732/2020/c22646b9-6c58-464e-b416-617901b561f2.jpg) with some fairly mild deconvolution; really struggled getting a good star mask. It certainly doesn’t have that “look” but in some respects it hasn’t been pushed as hard.

This was taken with the Mewlon 250 under ~1.4-1.8” seeing. It’s taken at 0.4”/pixel.

[strongmanmike]

Thanks for that Col, all makes sense now, the original looks much better to me though overall, nearly as detailed as your latest but more realistic and natural looking, the fine detail looks undoctored...it needs the stars too ;) . As I suspected and others efforts have also demonstrated, while clearly useful, these new tools are not as good as better seeing, a finer image scale and longer exposures :thumbsup: and look like they can easily impart an unrealistic, forced look to the image. I recall your fabuloso Keyhole now :thumbsup: and your beautiful result, taken under similar seeing conditions available to me regularly now, reflects your twice as fine image scale :thumbsup: You have illustrated well to me why I have felt the need to reduce my image scale now, in order to take advantage of the improved seeing at my new location....what to do :question: :scared:.. so THANKS! :rolleyes: :lol:

Mike

[Atmos]

I’m looking forward to the seeing improving. Having changed cameras (QHY600) and telescope (BeamTech 250) I’m now at 0.53”/pixel which should yield a better SNR and not sacrifice any potential resolution. The seeing for me during 2022, on the few clear nights between Jan and Nov, weren’t great. Now that I’m getting a few more clear nights I’m hoping that the seeing starts improving, been a struggle getting under 2.5” recently. I’ll see a few preliminary exposures come in at 1.8” just after sunset but it just gets worse as the night goes on.

When the dryer weather hits and the winds change, bring on 1” seeing!!

[strongmanmike]

Yeah, it would be good huh?...have to see it to believe it though :prey: :thumbsup: Your 0.5"/pix will be perfect...my 0.84"/pix will feel a little inadequate :( but should still see an improvement..? :)

Here's hoping 🙏

Mike

[Stefan Buda]

Hi Colin,

I suggest that you turn off the thermal control of your scope a bit before you start capturing your images and don't turn it back on unless there is a danger of dew forming on the mirrors. I did more testing of the thermal control on SN003 before sending it to NZ and it seems that in certain conditions it may interfere with the optical performance of the scope.
So I changed a parameter in the firmware that should prevent that from happening. I need to have your controller's firmware updated.

Cheers,
Stefan

[gregbradley]

Wow, that is sharp and detailed.
Latest processing developments are revolutionising our pursuit.

Greg.

[Atmos]

Hey Stefan,

In a very unscientific analysis, I took a 30s image of NGC 2070 with the fans running and then a few minutes later another 30s image without the fans and the FWHM did drop a bit so I'll leave them off for the rest of the night and see what happens. It does get pretty dewy where I image but who knows what'll happen.
FWHM went from around 1.7" to 1.5" ish so it's actually a good night!



Thanks Greg! As Mike has mentioned, there is some unnaturalness that comes from these sharpening plugins but damn they're so easy!