Cassiopeia Observatory

D7000 DSLR Imaging: Moon, ISS-Moon Transit Tests

Posted: 20 December 2012

On Tuesday, I received an alert from CalSky that the International Space Station (ISS) would transit the moon during the afternoon on Thursday from my location:

Won't be much of a transit but I hope to image it. Currently, the weather forecast is for a partly cloudy sky.

As forecast, snow did arrive overnight Tuesday-Wednesday, leaving about 1". Wednesday morning, an image from my Live Webcam made the Tucson TV news:

They bumped the Kitt Peak webcam, which is normally shown in that corner. (Thanks Jeff!)

The sky cleared during the day on Wednesday, 19 December 2012, so in the late afternoon, I went to the observatory and removed snow from the dome. Although the temperature had risen to 56°F during the day, there was still snow on the dome. The observatory was then opened at 1807 MST, 44°F. At 1816 MST, viewed the First Quarter Moon at 77X and 222X. Seeing was not very good, but the 2" 9mm 100° eyepiece (222X) yielded some nice views along the lunar terminator. I then viewed Jupiter, 222X. Four moons were visible, but seeing was not good enough for clear viewing of the planet. Switched back to 77X; little improvement.

Switched from the star diagonal to a visual back for prime focus imaging of the moon with the D7000 DSLR. This is 1/400sec, ISO 400:

I then synced the observatory clock to WWV so that I would have an accurate time display for the ISS-moon transit the next day. Next, I added a 2X Barlow Lens to the visual back. Unlike my first ISS-moon transit imaging in November 2011, which was taken at prime focus, I decided I would try some additional magnification on this second transit. I focused the D7000 DSLR on the moon and locked the telescope focus. The focus would remained locked in case I had limited opportunity to refocus prior to the transit. I then did a test HD video recording of the moon, 1/1250sec, ISO 5000. This would be my target exposure settings for the daytime transit. This is a frame from that video:

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