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The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge

The Cat's Eye Nebula - A Lucky Imaging Hybrid

Revision title: Newly added Ha.

Acquisition type: Lucky imaging
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The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge

The Cat's Eye Nebula - A Lucky Imaging Hybrid

Revision title: Newly added Ha.

Acquisition type: Lucky imaging

Acquisition details

Dates:
May 31, 2022 ·  June 1, 2022 ·  June 2, 2022
Frames:
Astrodon 50 mm 5 nm Ha: 22×60(22′) (gain: 100.00) -5°C bin 2×2
Astrodon 50 mm G: 56×60(56′) (gain: 100.00) -5°C bin 2×2
Astrodon 50mm B: 44×60(44′) (gain: 100.00) -5°C bin 2×2
Astrodon 50mm L: 1200×1(20′) (gain: 300.00) -5°C bin 1×1
Astrodon 50mm R: 60×60(1h) (gain: 100.00) -5°C bin 2×2
Integration:
3h 22′
Darks:
20
Flats:
60
Flat darks:
60
Bias:
20
Avg. Moon age:
1.82 days
Avg. Moon phase:
4.28%
Mean SQM:
21.50
Mean FWHM:
1.50

Basic astrometry details

Astrometry.net job: 5831041

Resolution: 1567x991

File size: 246.1 KB

Data source: Backyard

Description

My very first attempt at the Cat's Eye was in 2016 in an 8"... https://www.astrobin.com/259349/D/

I then re-processed in 2020 using everything I've learned over 4 years...  https://www.astrobin.com/78sxz7/

My third attempt would be with a 24" in very steady and dark skies. It would need to be very different.  

Here's a quick project summary for this "Lucky Imaging Hybrid"...

1. Only the core luminance uses Lucky Imaging. I captured 14,358 frames, 500 ms, 300 gain. The night was VERY steady with FWHM very close to 1", like the M106 night. This image uses the best 1,200 frames (10 minutes). With the bright core light captured with 24" and the very low noise of the CMOS, there was no noticeable advantage to using more and a slight decrease in SNR to use much less.

2. The lucky imaging result was deconvolved (500 iterations) using my PSF from the equally steady M106 night. There is no further sharpening (i.e., no wavelets, no HPF, no unsharp mask...).

3. RGB used the best 1 minute subs from 1 hour of each channel. FWHM was not great that night (2-3") so I deconvolved each RGB channel with its own PSF before combination. This helped a bit. I attempted RGB Lucky Imaging, but 500 ms exposures are just not deep enough for what I was aiming for. And the extra color resolution was not that noticeable.

4. SharpCap was used for SER file capture and PIPP (Surface Feature mode) was used to select, align and output 1,200 16-bit 640 x 480 bin 1x1 subs. They were then stacked in PI.

Could I improve this? I think color-wise, yes (i.e., lower FWHM RGB and possibly added Ha). But I don't think I could capture noticeably better core luminance.

As always, feedback is greatly appreciated!

KG

Comments

Revisions

  • The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge
    Original
  • The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge
    B
  • The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge
    C
  • Final
    The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge
    D
  • The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge
    E

B

Title: My Hubble reference.

Uploaded: ...

C

Title: Added 22 x 60s of lowest FWHM Ha (<1.6") from 155 subs.

Uploaded: ...

D

Title: Newly added Ha.

Uploaded: ...

E

Title: 18 x 60s of the lowest FWHM OIII from 180 subs. Not used in the final as the Ha in the core area overpowered it.

Uploaded: ...

Histogram

The Cat's Eye Nebula - A Lucky Imaging Hybrid, 



    
        

            KuriousGeorge

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