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Contains:  NGC 7380
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NGC-7380 (Wizard Nebula), 





    
        

            Joel Shepherd
NGC-7380 (Wizard Nebula)

NGC-7380 (Wizard Nebula)

Technical card

Resolution: 1920x1643

Dates:Sept. 24, 2018Sept. 26, 2018Sept. 27, 2018Sept. 28, 2018Oct. 14, 2018

Frames:
Astrodon 1.25" 3nm SII: 30x600" bin 1x1
Astrodon 3nm OIII 1.25: 30x600" bin 1x1
Astrodon 5nm H-alpha: 30x600" bin 1x1
Baader Planetarium B 1.25": 10x180" bin 1x1
Baader Planetarium G 1.25": 10x180" bin 1x1
Baader Planetarium R 1.25": 10x180" bin 1x1

Integration: 16.5 hours

Avg. Moon age: 14.16 days

Avg. Moon phase: 81.75%

Bortle Dark-Sky Scale: 6.00

Astrometry.net job: 2336053

RA center: 341.820 degrees

DEC center: 58.032 degrees

Pixel scale: 2.076 arcsec/pixel

Orientation: 5.868 degrees

Field radius: 0.729 degrees

Locations: Home, Seattle, WA, United States

Data source: Backyard

Description

NGC-7380 in SHO.

Processing on this started off normally -- calibration and tone-mapping the narrowband channels -- and then went off the rails. Normally, I'd create a synthetic luminance by combining the original Ha with the O-iii and S-ii tone maps. Unfortunately some of my Ha data was slightly out of focus with the result that I had to choose between bloated stars or severely clipped luminance.

Hmm. What to do. I ended up working over the combined tone map image more than usual: two rounds of LocalHistogramEqualization with a range mask to heighten contrast in the nebula, curves to increase overall contrast and restore a bit of saturation, MultiscaleMedianTransform with a small amount of bias at layers 1-5 to sharpen details, and a final round of curves for contrast. Then I added the RGB stars using PixelMath, and used a gentle round of SCNR on the background (nebula protected by a range mask) to desaturate the red channel a bit.

The result is probably a little less crisp than it would be with a proper luminance but I like that it captured faint nebulosity in the region and the stars were prettier than the hard white stars that tone-mapping + luminance usually produces.

Comments

Author

JoelShepherd
Joel Shepherd
License: Attribution Creative Commons
1851
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Revisions

  • NGC-7380 (Wizard Nebula), 





    
        

            Joel Shepherd
    Original
  • Final
    NGC-7380 (Wizard Nebula), 





    
        

            Joel Shepherd
    B

B

First upload was darker than intended: lightened background slightly.

Sky plot

Sky plot

Histogram

NGC-7380 (Wizard Nebula), 





    
        

            Joel Shepherd