Canon EOS 30D EOS 30D Instruction Manual - Page 108

Using EOS-Dedicated, External Speedlites Before attaching an external Speedlite, retract the built-in flash if it is popped up. If the EX-series Speedlite's firing mode is set to TTL autoflash with the Custom Function, the Speedlite will not fire. If autofocus cannot be achieved, the external, EOS-dedicated Speedlite's AF-assist beam (if the Speedlite has an AF-assist beam) will be emitted automatically (except in the modes). The camera is a Type-A camera that can use all the features of EXseries Speedlites. Using Non-Canon Flash Units Sync Speed The camera can synchronize with compact, non-Canon flash units at 1/ 250 sec. or slower shutter speeds. With large studio flash, the sync speed is 1/125 sec. or slower. Be sure to test the flash unit beforehand to make sure it synchronizes properly with the camera. PC Terminal The camera's PC terminal is provided for flash units having a sync cord. The PC terminal is threaded to prevent inadvertent disconnection. The camera's PC terminal has no polarity so you can connect any sync cord regardless of its polarity. If the camera is used with a flash unit or flash accessory dedicated to another camera brand, the camera may not operate properly and malfunction may result. Also, do not connect to the camera's PC terminal any flash unit requiring 250 V or more. Do not attach a high-voltage flash unit on the camera's hot shoe. It might not work. A flash attached to the camera's hot shoe and a flash unit connected to the PC terminal can be used at the same time. 108