Below are a couple of links to a private You Tube channel with some video clips for your viewing.

Here is a piece of video that captured on our DVR system at a courthouse we were investigating. We had only began recording after setting up our equipment and there was still daylight coming in the windows.
This is common example of dust. It may seem interesting for a moment but one must always look deeper into what they capture.

Cheers


http://www.youtube.com/watch?v=9EXF3Kb_reU

Video clip from the Kerrobert Courthouse basement hallway. There were a couple of instances where the sunlight crossing the hallway darkened.
We had just begun setting up equipment and began recording on the DVR system.
There was no one in the basement at the time.
I enter the area because we noticed something on the screen that looked like an area darkened.
I went down to investigate and sent two investigators to walkk back and forth across the windows to see if we could recreate this. They could not produce a shadow that cast any more than three past the window frames.
On evidence review I noticed this in the first 7 minutes. There was something in that room to the far right, but I am not sure what it could be.