Hemisphere:  Northern  ·  Constellation: Cygnus (Cyg)  ·  Contains:  Extremely wide field
Cygnus (Astrotracer), 



    
        

            AlenK
Cygnus (Astrotracer)
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Cygnus (Astrotracer)

Cygnus (Astrotracer), 



    
        

            AlenK
Cygnus (Astrotracer)
Powered byPixInsight

Cygnus (Astrotracer)

Technical card

Imaging telescopes or lenses: SMC Pentax-A 50mm f/1.4

Imaging cameras: Pentax K-3 II


Dates:Sept. 26, 2019

Frames: 16x60" ISO1600

Integration: 0.3 hours

Avg. Moon age: 26.89 days

Avg. Moon phase: 7.67%

Bortle Dark-Sky Scale: 4.00

Mean SQM: 20.90


Basic astrometry details

Astrometry.net job: 3329266

RA center: 20h 57' 45"

DEC center: +37° 44' 52"

Pixel scale: 31.033 arcsec/pixel

Orientation: 297.580 degrees

Field radius: 14.949 degrees


Resolution: 2888x1921

Data source: Traveller

Description

This was my first real test of a Pentax 50mm f/1.4 lens that I had recently acquired through eBay for less than $100US. Tracking was done internally with the camera's Astrotracer feature (no external tracker required).

This stack includes stops ranging from f/2.5 to f/4, including f/2.8, f/3.2 and f/3.5, with the majority being at f/2.8. Star shapes in the corners were acceptable to me from f/2.5 onward. Note that this lens is unusable for AP wide open at f/1.4; the stars are bloated messes. It is still unacceptable at f/2 except for, say, capturing meteors or aurora, where speed and aperture are more important than star shapes.

This image is a quarter resolution of the original frame with 4% cropping in each axis because of dithering. Stacked using Sequator, gradient reduction used DBE in PixInsight LE and stretched using rnc-color-stretch. No flats, bias or dark frames were used but I aggressively dithered and used kappa-sigma clipping during stacking.

The framing was intended to capture the areas around Deneb and Sadr as well as the Cygnus Loop (Veil nebulae, etc). Were I to do this over, I would frame it a little differently; rotated clockwise so that the Cygnus Loop is closer to the vertical center-line.

Comments

Revisions

  • Cygnus (Astrotracer), 



    
        

            AlenK
    Original
  • Final
    Cygnus (Astrotracer), 



    
        

            AlenK
    B

B

Description: Upgrade to quarter resolution (6Mpixel) from "2K" width (~2Mpixel).

Uploaded: ...

Sky plot

Sky plot

Histogram

Cygnus (Astrotracer), 



    
        

            AlenK