Copal 0 contact time?

[Mitch Feinberg]

Hello

I'm looking to emulate a copal 0 flash sync with a MultiMax. Anyone know the contact time when the shutter opens and closes (If they are different) ? This is NOT the shutter speed, but the length of time the circuit is closed to signal a flash or motor drive to fire (and if applicable, to stop running once the shutter closes). It should be very short, in hundreds of a second.

Much thanks

- M

[Neal Chaves]

I looked into these matters when I produced a device I called the Ghostmaster, the patent now in public domain. We speak now of Copal O, because other shutters can be quite different.

https://patents.google.com/patent/US5530320A/en

The flash contacts close when the blades have flown fully open. They open again just as the shutter starts to close and as the tips of the shutter blades just intrude into the aperture.

However, all mechanical switch contacts bounce upon closure, so some type of "debouncing" circuitry is usually required especially if determination of the "break time" is critical.