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Imaging: Gibbous Moon

Posted: 11 October 2016

Open: Monday, 10 October 2016, 1805 MST
Temperature: 89°F
Session: 1020
Conditions: Mostly clear

Equipment Used:
12" f/8 LX600 w/StarLock
Wireless AutoStar II handset
2" 24mm UWA eyepiece
Binoviewers 20mm
8-24mm zoom eyepiece

D7200 DSLR
iPhone 6s Plus

1812 MST: LX600 ON, StarLock OFF, High Precision OFF.

First, viewed the gibbous Moon, 102X. Then viewed Venus, 102X. A slight gibbous phase was visible. Next, viewed Saturn, 102X. The view was pretty good with the Ring showing nicely. Last, viewed Mars, 102X. But it was too small for good viewing.

1825 MST: began measuring the "exit pupil" of each of my eyepieces. Here are the results:

2" 50mm = 7.5mm
1.25" 40mm = 7mm
2" 30mm = 5mm
1.25" 26mm = 3mm
2" 24mm UWA = 1mm
1.25" 15mm = 2mm
1.25" 9.7mm = 1mm
2" 9mm 100° = 1mm
1.25" 5.5mm = 1mm
Binoviewers 20mm = 2.5mm

For comparison, my pupil sizes are: 2mm (day) and 5mm (dark adapted).

1847 MST: completed the measurements.

Did some lunar observing using the William Optics Binoviewers, 122X. The view of the gibbous Moon using the Binoviewers was AWESOME! Earthshine was still visible this night. Unfortunately, thin clouds were now in much of the sky, including where the Moon was. I then did some lunar observing using the Baader Zoom 8-24mm Eyepiece. The view at 305X (8mm) was pretty good even with thin clouds hampering the view.

1900 MST: set up for lunar imaging with the D7200 DSLR at prime focus + focal reducer. This is a 1/500sec, ISO 200, exposure, with saturation increased to bring out some color on the Moon:


This image, 1/2sec, ISO 400, through thin clouds, shows the Earthshine:


1910 MST: completed prime focus imaging. Set up to photograph the Moon projected onto the observatory dome. Mounted the iPhone 6s Plus on a GorillaPod and used a fisheye clip-on lens. I wasn't able to get a great photo as I didn't get the lens properly aligned nor properly focused, both due to the low illumination level inside the observatory with the red rope light off. But here is the photo using NightCap Pro (Long Exposure, Light Boost, ISO 5000, 1/3sec, 22 seconds):


The Moon is visible on the dome with the telescope faintly visible. The Apple Watch was used as a remote shutter release. I plan to do another "Moon on Dome" photograph on the next session. You can see past "Moon on Dome" photos on the Observatory Astrophotography Album.

1924 MST: with clouds now in lots of the sky, I began closing up.

Close: Monday, 10 October 2016, 1938 MST
Temperature: 75°F
Session Length: 1h 33m
Conditions: Partly cloudy

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