Hemisphere:  Northern  ·  Constellation: Cepheus (Cep)  ·  Contains:  Iris Nebula  ·  NGC 7023  ·  VdB139
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NGC 7023 - The Iris Nebula, 



    
        

            Steve Ludwig
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NGC 7023 - The Iris Nebula

Getting plate-solving status, please wait...
NGC 7023 - The Iris Nebula, 



    
        

            Steve Ludwig
Powered byPixInsight

NGC 7023 - The Iris Nebula

Acquisition details

Dates:
Sept. 21, 2020
Frames:
78×300(6h 30′)
Integration:
6h 30′
Avg. Moon age:
4.63 days
Avg. Moon phase:
22.36%

RA center: 21h01m38s.21

DEC center: +68°1016.5

Pixel scale: 1.197 arcsec/pixel

Orientation: 35.753 degrees

Field radius: 0.503 degrees

More info:Open 

Resolution: 2478x1729

File size: 739.5 KB

Data source: Backyard

Description

Equipment

- Main scope: Bresser Messier 10" Newton (254/1270)

- Main camera: Nikon D3300 (unmodified)

- Guide scope: Orion AC 50/162 Deluxe Mini

- Guide camera: ZWO ASI 290MC

- Mount: Skywatcher EQ6-R

- Explore Scientific HR coma corrector

Acquisition

- 78 lights x 300 s = 6 h 30 min

- no dark, flat, bias frames

- no filters

- ISO 800

- Bortle 4

Processing

- stacked in DSS

-> bilinear debayer method & median kappa sigma clipping

- unmodified TIF opened in PixInsight

-> STF stretch

-> dynamic crop

-> dynamic background extraction

-> background neutralization

-> color calibration

-> histogram transformation

-> Starnet++ to separate stars and background

Stars

-> SCNR green

-> invert

-> SCNR green to remove purple star edges (purple before inversion, now green)

-> invert

-> Curves transformation to increase saturation

Background

-> SCNR green

-> local histogram equalization to bring out detail in core

-> masked stretch to increase contrast of background dust

-> curves transformation with lightness mask to increase saturation of nebula core

-> curves transformation with lightness mask to decrease saturation of dust & background

-> massive ACDNR to reduce noise in background dust using the same mask

-> curves transformation without mask to balance overall brightness

-> pixel math to recombine stars and background

-> ACDNR to reduce noise

-> resample 50%

-> final curves transformation (fine tuning)

-> saved as jpg

Comments

Revisions

  • NGC 7023 - The Iris Nebula, 



    
        

            Steve Ludwig
    Original
  • NGC 7023 - The Iris Nebula, 



    
        

            Steve Ludwig
    H
  • Final
    NGC 7023 - The Iris Nebula, 



    
        

            Steve Ludwig
    I

H

Description: For this revision I separated the backround with the Pixinisght "Starnet++" plugin. Then I masked the bright core and stretched only the background. After using the "convolution" module on the resulting bright dust to reduce noise, I recombined the resulting background image with the stars.

Let me know in the comments which revision you prefer. The darker or brighter one?

Uploaded: ...

I

Description: For the latest revision I increased the color saturation a bit.

Uploaded: ...

Sky plot

Sky plot

Histogram

NGC 7023 - The Iris Nebula, 



    
        

            Steve Ludwig

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