Hello & welcome, LabMonkey !
It needs to work on an SD 1100 IS.
It should have as fast a shutter speed as possible (with the caveat that the SD1100 has no aperture or TV settings, only an ND filter).
It should detect motion (blue light intensity changes) as quickly as possible.
It takes a sequence of photographs as fast as possible after motion is detected.
In general, this could be done with
fudgey's fast MD script (see also
here) and the correct camera setup...
Use the camera in custom timer mode, with fix ISO, optionally fixed exposure time (Tv override), either with flash (adjustable with the CHDK force flash setting) or with a strong light source.
Set up MD to your needs in the script settings, e.g. set up a mask if you want to use only a part of the screen...
With Canon's custom timer mode the MD script starts capturing the images when motion is detected, IMO on the the SD1100 you can select up to 10 shots (in custom timer / "drive" menu, don't forget to set delay time to 0).
It would be really nice to get more than one image using the camera, since only one frame of the video has the event. I wrote a script that simply takes a series of no-flash photographs, but even that had significant delay between shots.
The camera is
to slow to capture such a fast series of images; a video typically has 25 or 30 fps - the SD1100 can take
~1.3 images per second in continuos mode, that's the highest fps you'll get.
FYI - the MD reaction time for the Powershot cameras is somewhere around 60 to 180 ms...
