Hi, quick question. The Canon S100 is capable of 2 pictures per second just by pressing the shutter button. So when running 3DR's CHDK script, why is this rate crippled at one picture every 2 seconds? Is there some other advantage aside from being able to trigger over USB? One picture every 2 seconds is fine for orthophotos, but unbearably slow for 3d mapping. I'm considering just getting a solenoid to press the shutter button using the relay from the pixhawk.
The Canon S100 will only shoot at 2 pictures per second if you put the camera into "Continuous Mode' using the Canon shooting menu. But be aware that when you do that, the camera sets exposure and locks focus on the first shot and all subsequent shots are taken at that same focus and exposure setting. This might be fine for shooting from a fixed wing aircraft but that's up to you. Also, if you use ISO values above 800, or try to save RAW images, the shooting slows down a lot!
On the other hand, the "3DR CHDK script" triggers a new picture for each shot with the focus and exposure being reset between shots. So each shot takes longer.
There is a way around this but it involves using the latest version of the script that was borrowed to create the 3DR script. Details of the original script can always be found here : CHDK KAP UAV Exposure Control Script .
The CHDK forum thread contains a lot of details about the most recent high speed shooting version of the script starting here : CHDK Forum : KAP & UAV Exposure Control Intervalometer Script T...
As of mid-July, the script allows an S100 (or S110 or other high end Canon P&S) to shoot at rates above 1 shot per second synchronized by a pixhawk servo output to the UAV's distance traveled over the ground. Testing continues and a non-Beta release is expected shortly.
Will that help ?