Hemisphere:  Southern  ·  Constellation: Orion (Ori)  ·  Contains:  Flame Nebula  ·  Great Orion Nebula  ·  IC 426  ·  IC 430  ·  IC 431  ·  IC 432  ·  IC 434  ·  Lower Sword  ·  M 42  ·  M 43  ·  Mairan's Nebula  ·  NGC 1975  ·  NGC 1976  ·  NGC 1977  ·  NGC 1980  ·  NGC 1981  ·  NGC 1982  ·  NGC 2023  ·  NGC 2024  ·  NGC 2064  ·  NGC 2067  ·  Orion B  ·  Orion Nebula  ·  Part of the constellation Orion (Ori)  ·  The star 29Ori  ·  The star 42Ori  ·  The star Alnilam (εOri)  ·  The star Alnitak (ζOri)  ·  The star Mintaka (δOri)  ·  The star ηOri  ·  And 5 more.
Orion Through a Window! (Astrotracer), 


Orion Through a Window! (Astrotracer)
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Orion Through a Window! (Astrotracer)

Technical card

Imaging telescopes or lenses: SMC Pentax-M 100mm f/2.8

Imaging cameras: Pentax K-3 II

Dates:Nov. 23, 2019

Frames: 26x30" ISO400

Integration: 0.2 hours

Avg. Moon age: 26.10 days

Avg. Moon phase: 12.77%

Bortle Dark-Sky Scale: 7.00

Basic astrometry details

Astrometry.net job: 3980681

RA center: 5h 36' 18"

DEC center: -3° 12' 28"

Pixel scale: 16.081 arcsec/pixel

Orientation: 353.877 degrees

Field radius: 5.903 degrees

Resolution: 1466x2199

Data source: Backyard


This was a whimsical attempt to photograph Orion (or rather part of it) through a closed window from inside my house. Tracking was accomplished in-camera using the camera's Astrotracer feature with the camera mounted directly on a tripod. Fortunately, Astrotracer does not require polar alignment (the NCP was of course completely blocked from view inside the house). The lens was stopped down to f/4.

The sightline to Orion was unfortunately not at right angles to the glass, so there were numerous reflections from the brighter stars in the image. Those were laboriously removed with the clone tool.

Another side effect of shooting through a window at an angle is that the tracking required for pin-point stars was not uniform across the image owing to the effects of refraction through the angled glass. Hence, some stars are round but most are not.

I would not recommend astrophotography through a window but it did allow me to get a recognizable image of the belt and sword of Orion that I probably would not have stepped outside to take that night.


Sky plot

Sky plot


Orion Through a Window! (Astrotracer),