Safe Sync - How to Connect Old Flash Units to Newer Cameras

As mentioned earlier, attaching an older flash unit with more than single digit voltage at the contacts can and will damage your newer electronic camera. These flashes can be used with any older camera that has a mechanical shutter mechanism (i.e. no battery is required to use the shutter on the camera), but newer cameras, not.

However, there is a solution, if you have a collection of older flash units that you would like to use. That is, with a Safe Sync. A simple device that attaches to the hotshoe of your camera and that regulates the voltage from your flash unit to your camera. Beware, eBay and others have units that look like a Safe Sync, but they are not Safe Sync units. Using such a device with a flash that has a 100V trigger could spell the end for your camera.

Look carefully before you buy and connect your older flash unit to your new age camera.

StackExchange has a short article on Safe Sync units.