Yesterday I used Camtasia on my laptop to record two classes from my first year module G11FPM Foundations of Pure Mathematics (Lecture 2: Sets and Numbers and Workshop 1: About this Module) These are available as streaming video (requires flash player) from:
Unfortunately, my laptop was struggling, and the audio ends up several seconds out of sync (and with some bits missing). I have deliberately stopped the picture-in-picture bit after a few minutes, because the lack of synchronization becomes even more disturbing otherwise.
One possible cause of the problems is that the power at the mains socket I used might have been switched off. That does produce this sort of effect, but I don’t think that happened in this case. My current theory is that the problems come from my laptop shaking too much and going into hard-disk protection mode.
The reason the laptop shakes so much is that I have the laptop on a laptop stand on top of a box in order to get some extra height and a better angle. (I want my face to be visible when I am writing.) It would be fine if I forced myself to write slowly and gently, but I find this hard to do when explaining something enthusiastically! So next time I record this way, I will do without the laptop stand, and I will just use the plastic box for extra height. Perhaps that will cure the problem. I will report back sometime!