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Final D850 DSLR ISO tests,
Triangulum Galaxy, Dumbbell Nebula

Posted: 11 November 2021

Tuesday, 9 November 2021, began cloudy, cleared by mid-day, but then clouded up again late afternoon. The sky was clear on Wednesday, 10 November.

Open: Wednesday, 10 November 2021, 1804 MST
Temperature: 74°F
Session: 1691
Conditions: Mostly clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
Focal reducer
2" UHC filter


1807 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Venus, Saturn, and Jupiter, 102X.

Viewed the Moon, 102X.

Mounted the D850 DSLR at prime focus + focal reducer.

The Moon, 1/400sec, ISO 200, White Balance 4550K.


Slewed to the star Mirach. Added the UHC filter for later imaging.

1825-1914 MST: relaxed on the observatory patio bench. Monitored the thin clouds that were visible. Watched the launch of the NASA astronauts on the SpaceX Crew Dragon.

Back at the 12" telescope, focused on Mirach, locked the 12" mirror, and slewed to M33 (Triangulum Galaxy) for my final D850 DSLR ISO tests. I did six StarLock autoguided images of M33, 5 minutes, ISO 800, WB4550K. I then did six StarLock autoguided images of M27 (Dumbbell Nebula), 5 minutes, ISO 800, WB4550K. The following are stacks of the six M33 images and five of the M27 images (one was ruined by a satellite crossing the nebula).

M33 (Triangulum Galaxy)

M27 (Dumbbell Nebula)

I have updated my D850 DSLR ISO Tests article with these final results, showing the unedited, edited, and stacked images.

Viewed M27 (Dumbbell Nebula), 102X.

104` MST: LX600 OFF.

Close: Wednesday, 10 November 2021, 2048 MST
Temperature: 56°F
Session Length: 2h 44m
Conditions: Mostly clear

Check out the Asteroids & Dwarf Planets Astrophotography album. I have added links to pages with asteroids named for Friends and Places that have meaning to me.

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