There's some info about this problem here.
http://chdk.setepontos.com/index.php?topic=9597.0I've been wondering if it would be possible to set the clock with msec accuracy triggered by an outside pulse. To set the clock in the Canon menu, you first put in the right time, and then press <SET> to start the clock. Maybe you could use the remote USB switch to press <SET> at the exact time. Or maybe there's a firmware function to start the clock that could be called directly?
This could solve the multiple camera sync problem without using any wires. All the cameras could just start taking pictures every second in sync. And maybe cameras with a GPS chip could sync to GPS time? Isn't that the same on all cameras with a GPS chip?
You don't really have to know the precise time of a random shot. You would just need to take all shots when the GPS seconds time changes. That is, delay taking a shot right before shutter open until GPS seconds changes. That way, all the shots would be in sync with any GPS.
