Hemisphere:  Southern  ·  Constellation: Orion (Ori)  ·  Contains:  41 the01 Ori  ·  43 the02 Ori  ·  De Mairan's nebula  ·  Great Orion Nebula  ·  M 42  ·  M 43  ·  Mairan's Nebula  ·  NGC 1976  ·  NGC 1982  ·  Orion Nebula  ·  Sh2-281  ·  The star θ1Ori  ·  The star θ2Ori
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M42 - The Orion Nebula, 



    
        

            Steve Ludwig
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M42 - The Orion Nebula

Getting plate-solving status, please wait...
M42 - The Orion Nebula, 



    
        

            Steve Ludwig
Powered byPixInsight

M42 - The Orion Nebula

Acquisition details

Dates:
Nov. 6, 2020
Frames:
113×150(4h 42′ 30″)
Integration:
4h 42′ 30″
Avg. Moon age:
20.13 days
Avg. Moon phase:
70.83%

RA center: 05h34m58s.20

DEC center: -05°2454.8

Pixel scale: 1.197 arcsec/pixel

Orientation: 35.005 degrees

Field radius: 0.552 degrees

More info:Open 

Resolution: 2815x1762

File size: 1.8 MB

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

- 113 lights x 150 s = 4 h 42 min

- no dark, flat, bias frames

- no filters

- ISO 200

- Bortle 4

Processing

- stacked in DSS

-> bilinear debayer method & median kappa sigma clipping

- unmodified TIF opened in PixInsight

-> STF stretch

-> rotation

-> crop

-> dynamic background extraction

-> background neutralization

-> color calibration

-> histogram transformation

-> multiscale linear transform to sharpen the whole image

-> use of starnet++ module to separate background and stars

-> multiscale linear transform to further sharpen background only

-> pixel math to recombine background and stars

-> resample 50%

-> ACDNR with lightness mask to reduce noise of darker areas

-> final curves transformation to increase overall brightness a bit

-> saved as jpg

New in Revision B

-> masked stretch to increase contrast of dark regions

-> masked ACDNR to reduce noise in the areas that have been brought out by masked stretch

-> curves transformation to increase overall saturation

-> histogram transformation to lower black point by 5%

-> background neutralization o remove bluish tint from the image

-> saved as jpg

New in Revision C

-> histogram transformation: black point increase of red channel to get more neutral background

-> histogram transformation: overall black point increase to undo half of the black point reduction from revision B

New in Revision D

-> TGV Denoise with maximum edge protection and low strength to decrease noise without losing details or dim stars

Comments

Revisions

  • M42 - The Orion Nebula, 



    
        

            Steve Ludwig
    Original
  • M42 - The Orion Nebula, 



    
        

            Steve Ludwig
    C
  • M42 - The Orion Nebula, 



    
        

            Steve Ludwig
    D
  • M42 - The Orion Nebula, 



    
        

            Steve Ludwig
    E
  • Final
    M42 - The Orion Nebula, 



    
        

            Steve Ludwig
    F

C

Description: Some further histogram fine-tuning: I increased the black point of the red channel a bit to get a slightly more neutral background. Furthermore, I increased the overall black point a bit (+0.025) after filling in some zeros at the low end in the revision before.

Uploaded: ...

D

Description: For revision D, I applied another run of "TGV Denoise" with low strength and maximum edge protection. This helped to further reduce noise without losing fine details and dim stars. Furthermore, I slightly cropped the image to get rid of the distractive Iota Orionis star halo.

Uploaded: ...

E

Description: In revision E, I used another run of ACDNR to reduce noise in the outer, dark regions of the image. Now there is a smooth transition between bright and dark parts. I'm really happy with how it turned out in the end. ;)

Uploaded: ...

F

Description: After hesitating to apply any HDR processes to my M42 image, I finally tried it. Actually, I really like M42 with a natural, bright core. However, in the latest revision I tried to bring out more detail in the core without losing too much of its brightness. To achieve that, I applied the following process steps:

- HDR Multiscale Transform to bring out detail in the core
- SCNR green to remove greenish tint (especially around the core)
- Pixel Math to blend the earlier version with the HDR version (70%/30%) which gave a good balance of detail and brightness
- Curves Transformation to increase saturation a bit

Uploaded: ...

Sky plot

Sky plot

Histogram

M42 - The Orion Nebula, 



    
        

            Steve Ludwig