How to do <=1 Hz timelapse photography with Canon 7D? I'd like to take 1 Hz and sub-second timelapse videos with my Canon 7D. I've tried both DslrDashboard and Magic Lantern, and couldn't figure out how to set the timelapse any faster than that. Worse, both of them ended up taking photos at such a jittery rate that I could hear it was completely off kilter. The camera would take one photo, then wait for a couple seconds before taking two in less than half a second, and so on, making the result unusable for video making. I was using manual mode, and shutter time, f-stop and ISO were all set to static values.

The camera is otherwise perfectly capable of taking many photos per second, even at RAW quality. Is there some fundamental issue with the timing used when remote controlling (and even when using custom firmware) causing this, or did I miss an important setting to make it all work? If this is simply an issue with both these products, are there other software products (preferably FOSS) which will reliably take 1 Hz or faster time lapse series?

(Repost from photo.SE after suggestion.)
The problem isn't the remote timing, it's the rate at which data can be written to the SD or CF card.  The camera can shoot a bunch of images quickly in burst mode because it stores them in an internal buffer for a short while before it writes them to memory.  However, this pace of data acquisition is not sustainable for long periods of time because the buffer will fill up before it can offload to the card.  The best thing you can do is make sure you're using cards with the fastest write speed possible.  Shooting jpeg only might also help, depending on how quickly the camera converts RAW to jpeg.