Here's an unusual one - a thermal sensor actually scanning. You'll probably have to click the image to see the animated GIF or a
higher resolution version of the file on the Flickr site.
This is quite remarkable: I pointed a 25Hz Therm-App camera at the sensor of another Therm-App camera and I could actually see the scanning in progress!
The frame rate of the two cameras differs slightly, which is how come we can see this effect. What you're seeing is the sensor on top of the ROIC (read-out IC) becoming
very slightly warmer as each row is read out. This is actually happening 25 times a second but because the two cameras are running at nearly the same frame rate we get a kind of 'stroboscopic' effect, very like the effect you used to see on TV screens being filmed.
There's a decent description of why a filmed TV screen appears to flicker (which works in the same way)
here if you want to know more, and the
short movie linked from that page shows exactly what's going on.
I found it utterly fascinating to see, and I've never heard of anything similar being filmed before. This is definitely not caused by any other artifact such as a lighting effect or anything physically moving, and when I swapped the cameras round I saw exactly the same effect - but with the motion going in the opposite direction.