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Cloudy Sky; Coolpix P900 Venus, ISS

Posted: 9 June 2018

Pre-Monsoon Season clouds (unforecasted) were in the southeastern sky during most of the afternoon on Friday, 8 June 2018. Monsoon Season starts 15 June.

In my review of the Nikon Coolpix P900 digital camera I wondered if the camera could be used to photograph the International Space Station (ISS). As there would be a good pass of the International Space Station (ISS) this night I decided to open the observatory and try a test with the P900.

Open: Friday, 8 June 2018, 1922 MST
Temperature: 84°F
Session: 1247
Conditions: Partly cloudy

Equipment Used:
12" f/8 LX600 w/StarLock
2" 24mm UWA eyepiece

Coolpix P900

1929 MST: clouds in the southern sky:


1933 MST: sunset.

I then did some experimenting with the P900 using the planet Venus as a stand-in for the Space Station. I took this photo, f/6.5, 1/800sec, ISO 800, FL 2000mm (35mm equivalent):


Venus is at the center. The inset shows a magnified view with the slightly gibbous phase of Venus clearly visible.

I also did a video recording to test my ability to handhold the camera at FL 2000mm. The tests gave me some confidence that I could use the P900 to image the ISS. What didn't give me confidence was the increasing clouds in south (P900 photo):


1941 MST: LX600 ON, StarLock OFF, High Precision OFF.

Viewed Venus, 102X, and saw the same gibbous phase as was photographed with the P900 camera.

Then viewed Jupiter, 102X. The Great Red Spot and the four Galilean Moons were visible.

Next, did some planning for the night's imaging (with the D850 DSLR) for my Extragalactic Supernova Project, although I worried if the clouds would prevent imaging.

1948 MST: clouds in the south were getting higher in the sky. 1957 MST: the clouds had reached Jupiter. 2008 MST: the clouds had reached the zenith. DSO imaging looked unlikely this night. In fact I had my doubts about seeing the ISS pass, which would start at 2124 MST.

2012 MST: Kissing Bug #1 terminated.

2020 MST: the clouds were now in about 2/3s of the sky.

2025 MST: Kissing Bug #2 terminated. 2029 MST: Kissing Bug #3 terminated.

2032 MST: slewed to M104 (Sombrero Galaxy), which was planned to be the first galaxy imaging target of the night. It was faintly visible through some clouds, 102X.

2034 MST: Kissing Bug #4 was seen but it was too high on the dome to reach. 2038 MST: terminated.

2039 MST: had a better view of M104, 102X.

2040 MST: saw Kissing Bug #5 but it was too high on the dome. 2046 MST: the bug landed on the floor and was terminated.

2050 MST: some holes were appearing in the clouds. It might be good enough for the ISS pass.

2052 MST: while viewing M104, 102X, saw a satellite pass through the field-of-view.

2102 MST: due to the clouds I decided to give up on my plans for galaxy imaging this night. Took a last look at M104 (Sombrero Galaxy), 102X.

Kissing Bug #6 was terminated.

Last look at Jupiter, 102X.

2106 MST: LX600 OFF.

As the ISS pass began, the western sky where the path would be had only thin clouds. I began doing a video recording with the Coolpix P900, f/6.5, 1/800sec, ISO 800, FL 2000mm. I was able to track the ISS handheld as it rose to about 30° above the horizon. As it rose higher it became more difficult, but not impossible to track. The ISS entered the Earth's shadow at 42° altitude. Here are images of the ISS, cropped from four video frames:


The left image is with the ISS low in the sky and shows a definite shape with the solar panels. The next image is near the brightest portion of the pass and is overexposed. The third image shows the ISS as it began entering the Earth's shadow, dimming slightly. The fourth image is near the end of the visible pass, with reddening and dimming from the Earth's shadow, and shows some structure.

I learned two things from this first test of capturing the ISS with the Coolpix P900: (1) it is indeed possible to photograph the ISS with the long zoom lens of the P900, and (2) I need to use less exposure for a good bright pass. There is an excellent pass of the ISS Saturday night, 9 June. I hope to try again, if the (now forecasted) clouds don't block the view.

Close: Friday, 8 June 2018, 2140 MST
Temperature: 78°F
Session Length: 2h 18m
Conditions: Mostly cloudy

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