2004.11.24 - Learning to dislike the full moon.
The weather forecast said it was going to be clear tonight starting just after nightfall. I had a hard time believing this since the cloud ceiling was about 100' AGL all day. But, like clockwork, the clouds just magically shuffled off at about 5pm. However, they left behind a high thin layer that was semi-transparent but ubiquitous. Unfortunately, tonight's basically full moon made the entire layer of cirrus clouds glow brightly.
Bob and I went down to the overlook in White Rock and set up the telescope in Alt-Az. We were hoping the clouds would go away but it was pretty constant. We could see a few bright stars (enough to get an alignment) but there wasn't anything to look at other than the moon, so we were only out there for about an hour. No chance to calibrate the camera and test its aberration at various f-stops, which is what I was hoping to accomplish tonight.
2004.11.24 - Star trails first attempt
Of course, about 45 minutes after we packed up and left the overlook, the cloud layer went away and left behind a clear sky. The full moon still made observing pretty poor, but at least there were stars that could be seen. Regardless, we were no longer there to observe it.
I decided to put the camera on a tripod on my back deck and see if I could do some star trail shots. I did a series of shots with my new 50mm lens at various f-stops and exposure times. What I discovered was that even though the sky appeared much darker than it had when we had the telescope out, the fog limit was still quite short and the star trail shots were unimpressive to say the least.
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A comparison of the darkest portion of the
star trails shot. Top: 5 minutes at f/5.6. Bottom: 40 minutes at f/11.
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In order to compensate for the high sky brightness, I had to stop the lens down pretty far and this means that dimmer stars don't show up at all. In order to get longer, more aesthetic star trails, I really had to crank down the aperature. But when I did that, only a few stars were visible. In the end, I decided that the only thing worth observing on a full moon night was the moon itself.
I don't have a sufficient lens for doing piggyback photography of the moon, so until we get our through-the-scope photography setup working, these large moon nights are going to be pretty much useless.