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More D850 DSLR ISO Tests,
iPhone Globular Clusters

Posted: 7 November 2021

Open: Saturday, 6 November 2021, 1748 MST
Temperature: 84°F
Session: 1689
Conditions: Clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
1.25" 15mm eyepiece
2" UHC filter
Focal reducer

iPhone 13 Pro Max

1752 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed the Moon, 102X, low and through tree limbs.

Took this handheld afocal 102X image of the Moon with the iPhone 13 Pro Max using the NightCap Camera app (ISO 250, 1/60sec, 1X lens).


I then viewed Venus, Saturn, and Jupiter, 102X.

I prepared the D850 DSLR for imaging.

1808-1851 MST: Relaxed on the observatory patio bench while waiting for Astronomical Twilight to end.

After returning to inside the observatory, I mounted the D850 DSLR at prime focus + focal reducer + UHC filter to do some more ISO test imaging. Focused on the star Mirach, locked the 12" primary mirror, and SYNCed on Mirach.

This M33 (Triangulum Galaxy) image, StarLock autoguided, 5 minutes, ISO 6400, White Balance 4550K, edited, is just a sample of one of the images I'll post in my upcoming full article on the D850 DSLR ISO tests.


I viewed M33 (Triangulum Galaxy), 102X.

Then viewed M2 (globular cluster), 102X and 163X.

Mounted the iPhone 13 Pro Max on the 15mm eyepiece using the Levenhuk adapter. On my previous iPhone afocal imaging session I had noticed that my LiDAR cover would sometimes move as I was centering the camera lens over the eyepiece. I added a second clip from an old clip-on lens, which held the cover more tightly. I have updated my iPhone 13 Pro Max Afocal Photography LiDAR Issue article.


I took the following StarLock autoguided, afocal 163X, iPhone 13 Pro Max images using NightCap Cap (Long Exposure, Light Boost, ISO 16000, 1sec, 1 minute, 1X lens).

M2 (globular cluster)
M30 (globular cluster)

2033 MST: LX600 OFF.

2041 MST: Took a Sky Quality reading. The sky was brighter than expected.

Close: Saturday, 6 November 2021, 2044 MST
Temperature: 62°F
Session Length: 2h 56m
Conditions: Clear, SQM 20.90

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