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iPhone 13 Pro Max afocal tests with 3X lens

Posted: 12 November 2021

Open: Thursday, 11 November 2021, 1806 MST
Temperature: 74°F
Session: 1692
Conditions: Clear

12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
1.25" 15mm eyepiece

iPhone 13 Pro Max

1811 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Venus, Saturn, Jupiter, Moon, and Neptune, 102X.

Took this handheld afocal 102X photo of the Moon using the iPhone 13 Pro Max with the iOS app NightCap Camera (ISO 34, 1/1150sec, 1X lens).


Did some lunar observing, 163X. The crater Albategnius looked interesting.

I attached my prototype LiDAR cover on the iPhone 13 Pro Max, and then mounted the iPhone on the 15mm eyepiece using the Levenhuk adapter. Took this afocal 163X image of crater Albategnius through the 3X telephoto lens using NightCap Camera (ISO 200, 1/120sec, 3X lens).


I then began doing some afocal 163X imaging tests of Venus, Saturn, Jupiter, and Neptune using the iPhone 13 Pro Max 3X telephoto lens. Bright Venus was too overexposed (should have used an eyepiece filter). Saturn and Neptune were too faint in the eyepiece at 3X for a slo-mo (240fps) video recording. Jupiter was OK, but slightly overexposed with the slo-mo video using the 3X lens. Using the 3X telephoto lens for afocal imaging was difficult to focus. Here are the results of these initial 3X lens tests.

Saturn, NightCap Camera (ISO 640, 1/20sec, 3X)

Jupiter, Camera app (slo-mo, 240fps, 10 seconds, 3X, 1881 frames stacked)

Neptune, NightCap Camera (ISO 4000, 1/10sec, 3X)

1908 MST: viewed Uranus, 163X. It was a little too low in the eastern sky for imaging.

1910 MST: relaxed on the observatory patio bench while waiting for Uranus to rise higher.

1925 MST: saw a bright meteor pass Perseus and move into Auriga. Impressive.

1936 MST: back inside the observatory.

Imaged Uranus with the iPhone 13 Pro Max 3X lens, afocal 163X. It was barely visible on the iPhone screen when doing the video recording.

Uranus, Camera app (slo-mo, 240fps, 10 seconds, 3X, 1884 frames stacked)

1947 MST: LX600 OFF.

Close: Thursday, 11 November 2021, 1955 MST
Temperature: 61°F
Session Length: 1h 49m
Conditions: Clear

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