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D850 DSLR video tests;
iPhone Astrophotography Messier Catalog Objects

Posted: 3 April 2018

Open: Monday, 2 April 2018, 1831 MST
Temperature: 75°F
Session: 1218
Conditions: Mostly clear, breezy

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece
2" 30mm eyepiece
1.25" 15mm eyepiece
2" 2X PowerMate
Focal Reducer

iPhone 8 Plus

Delayed uncovering the telescope for a few minutes after opening the dome due to strong breezes.

1844 MST: LX600 ON, StarLock OFF, High Precision OFF. Breezes were calmer now.

The Sun set behind clouds.

Viewed Venus, 102X.

Mounted the D850 DSLR at prime focus + 2X PowerMate for some video resolution tests. I did video recordings at 1/500sec, ISO 320, using the following resolutions:

FX 720p 60fps
FX 1080p 60fps
FX 2160p 30fps
DX 720p 60fps
DX 1080p 60fps
DX 2160p 30fps

The videos using 2160p had the highest resolution, allowing for the greatest cropping. As expected, the DX crop mode provided a larger image than FX. These images of Venus were taken using 2160p 30fps with FX (158 frames stacked) on the left and DX (195 frames stacked) on the right:

photo photo

1901 MST: completed D850 video tests. Removed the camera. I will likely use DX 2160p 30fps video recordings for planets when I want to stack frames using Keith's Image Stacker.

Viewed Venus, 81X.

1907 MST: High Precision ON. Did a GOTO M51 (Whirlpool Galaxy) in preparation for imaging it with the iPhone 8 Plus for my iPhone Messier Catalog Astrophotography Album. The galaxy was not yet visible due to the bright twilight sky. High Precision OFF. 1930 MST: M51 now faintly visible, 81X.

1945 MST: mounted the iPhone 8 Plus on the 2" 30mm eyepiece.

1947 MST: StarLock ON.

Took this StarLock autoguided iPhone afocal 81X image of M51 (Whirlpool Galaxy) using NightCap Camera (Long Exposure, Light Boost, ISO 8448, 1/3sec, 5 minutes):

M51 (Whirlpool Galaxy)

Both components of M51 are visible as fuzzy dots with the larger component at the center. Some spiral arm structure is also visible in the iPhone image.

1956 MST: StarLock OFF.

Next, I mounted the D850 DSLR at prime focus + focal reducer to do some faint asteroid (Mag. +18.9) imaging. 2005 MST: Wi-Fi ON. Used SkySafari 6 Pro on the iPhone to GOTO the asteroid. 2007 MST: Wi-Fi OFF, StarLock ON.

I tried imaging but the seeing was not good enough (possibly due to some thin clouds) for autoguiding. Gave up. 2021 MST: StarLock OFF. Will try again to image this faint asteroid on a future session.

Removed the camera and viewed the following Messier objects, 102X: M3 (globular cluster), M63 (Sunflower Galaxy), M101 (Pinwheel Galaxy), M102 (galaxy). Switched to the 30mm eyepiece for iPhone imaging.

2034 MST: StarLock ON.

Took these StarLock autoguided iPhone images using NightCap Camera (Long Exposure, Light Boost, ISO 8448, 1/3sec, 1 minute):

M63 (Sunflower Galaxy)

M101 (Pinwheel Galaxy)

M102 (galaxy)

M63 and M102 show some structure but M101 was too faint to show much using the iPhone.

Switched to a 1.25" 15mm eyepiece for this StarLock autoguided iPhone afocal 163X image of M3 (globular cluster) using NightCap Camera (Long Exposure, Light Boost, ISO 8448, 1/3sec, 1 minute):

M3 (globular cluster)

2058 MST: StarLock OFF. The eastern sky was brightening due to the rising waning gibblous Moon.

Viewed M3 (globular cluster), 163X and 102X.

2108 MST: LX600 OFF.

Close: Monday, 2 April 2018, 2116 MST
Temperature: 61°F
Session Length: 2h 37m
Conditions: Partly cloudy

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