Time lapse video

I am using a web cam to capture pictures every 15 seconds over about an hour. I need to work on the focus. A sunnier day would have been nice. Here is one of the original frames. Click to enlarge.

What is interesting about this particular piece is that it was mostly overcast with a few bursts of sun. I had thought that the sensor didn't wander when there was cloud cover, but apparently it does. This is impossible to see in real time unless you have the patience I guess? When the sky is a solid gray, the sensor does not seem to wander. When there are clouds that obscure the sun for a time, the sensor may be mislead by the "silver lining" of the cloud which is brighter than the portion of the cloud that covers the sun. The good news is that the sensor recovers promptly when the cloud moves and the sun is clear once again.
Here is another attempt made this morning. The duration is about one half hour and the sensor is swinging the array from the west to catch the morning sun. Unfortunately, the sky clouded over AGAIN.

More soon.