Archived from groups: rec.photo.digital (More info?)
> Hi all,
> Can anyone tell me why my off camera flash (Vivitar), when used with a
> slave unit, does not sync with the on camera(Olympus C700UZ) flash ?
> Thanks much,
Your OLY C-700UZ probably has a preflash. (A small flash that the camera
uses to focus and set exposure.) It fires right before the main flash.
It is strong enough to trigger the Vivitar Slave.