Speed Graphic – Flash Sync with Bi-pole Lens & Focal Plane Shutters

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I’ve been meaning to write this post since February 2016 – two years ago… better late than never. I have finally got around to it following a query from someone on how I connected my flash to the Bi-pole connection on my lens and focal plane shutter of the Speed Graphic. Unfortunately the focal plane shutter on the speed graphic is designed for flash bulbs and so it doesn’t have an X-sync. I’d need to make some sort of delay circuit for that to work, which I doubt I’ll ever get around to. Using the connection on the lens is good enough for now.

The two pins sticking out of the Graphex shutter pictured below is called the Bi-pole connector. Make sure to have the sliding switch beside the connector set to F-X for modern electronic flashes (‘M’ is for old bulb flashes and the signal won’t trigger the electronic flash at the correct time if you have it set to this mode).

The two pins simply mechanically ‘short’ together at the right moment of the shutter release. It’s therefore possible to connect these pins to a suitable cable and then to a flash (of radio trigger) to sync a flash to your shutter. My first attempt to do this was to use two electrical terminal strip blocks (commonly and affectionately called ‘choccy blocks’). With these it’s possible to clamp a screw to each pin and provide a screw terminal to connect a suitable cable.

Next you need to source some suitable sync cables with the appropriate cable ends for the flash you’ll be connecting. I’ve used a flash extension lead that has a female end to it. I cut the other end off, stripped the wires and connected to the ‘choccy block’. This allowed me to do some test exposures to check the theory – all works well!

I improved my solution slightly by finding some crimps that perfectly fitted the pins, which makes a nice secure connection.

Hope this helps someone.

Here is a video of it working:

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