Scratchboard time-lapse videos

I've made several videos showing large scratchboards in a time-lapse progress fashion. That is, I set up a camera, set an intervalometer to take a still photo every minute or so, then stitched the hundreds (thousands?) of still shots all together in iMovie to create a video that compresses weeks of work into a few minutes.

The first video shows my 24x32 zebra scratchboard, "Homage to Muybridge":  

 

...and this one is of a 24x24 commission of a British Grand Prix horse:

 

The last video is not really a time-lapse; it was created in response to a suggestion that I show the painstaking nature of scratchboard in real time. So here are two minutes (for which you might need coffee) of actual progress on a large scratchboard: