X-rays caught on tape!

Source:  X-rays caught on tape!    Tag:  cool xrays
I recently bought a cheap DSLR, and because it's still shiny and new to me, I found myself wondering if it would pick up any evidence of the x-rays inside the scanner at the airport. So before running my carry-ons through, I put the lens cap on, pushed "record", and aimed it face-down near the top of a bag. Here is the result:

You can hear the rolly-bars on both ends, and I think the camera enters the x-ray machine around second 28, just after "okay, cool." Random pixels (red, blue, white) fire more and more as it nears the scanning area, and you can hear some machinery "clunks" correlated with bigger bursts of noise (maybe a shutter?).

The fun question now is what exactly are we seeing? And why do I still call it "tape"? (Hint: it is in no way related to this, which is totally cool for other reasons.)