PC Sync to flash?

Hello,
newbie here on the site, question about PC Sync. I think I understand the principle of what it does, especially with digital cameras, of film camera with batteries in them. Weird/possibly dumb question. How does a large format lens physically/electronically send a signal to PC Sync cord that sends it to the flash, as what is the power source??

..if i do understand correctly the PC Sync sends a small current/voltage to the flash???, where does this current/voltage come from on a large format lens??

any clarifications would be helpful.

Nick

Quote:

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Originally Posted by shifter

Hello,
newbie here on the site, question about PC Sync. I think I understand the principle of what it does, especially with digital cameras, of film camera with batteries in them. Weird/possibly dumb question. How does a large format lens physically/electronically send a signal to PC Sync cord that sends it to the flash, as what is the power source??
..if i do understand correctly the PC Sync sends a small current/voltage to the flash???, where does this current/voltage come from on a large format lens??

any clarifications would be helpful.

Nick

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On a mechanical LF lens the synch signal is a short circuit created when the shutter fully opens. The synch voltage comes from the flash. Current flash units have a low voltage synch but old flash units could have very high synch voltage. Low voltage synch units started with studio flash units like the Rollei E250 in the early 70s.

The PC circuit in a LF shutter is just a normally-open switch that closes momentarily to complete a circuit. Same with most mechanical-shutter cameras.

No electric power in lens or shutter

It's a mechanical switch, like a doorbell button

Further to the earlier comments, it is just a switch that closes at a particular time during he exposure ("X" sync for electronic flash).

The electrical power comes from the flash system.

Do however be aware that if you are using studio flash systems, it can be a lethal level of voltage and power.

Be careful...

Quote:

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Originally Posted by Len Middleton

Further to the earlier comments, it is just a switch that closes at a particular time during he exposure ("X" sync for electronic flash).

The electrical power comes from the flash system.

Do however be aware that if you are using studio flash systems, it can be a lethal level of voltage and power.

Be careful...

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And in that case, buy a Wein Safe-Sync with the proper connectors on it, ie: pc; 1/4" phono , or "H" , To go between the shutter and the strobe, or radio triggers, to reduce sync voltage to safe levels, and no worries.

Or something like a Pocket Wizard which trips flash via a radio signal. Short cable to shutter PC.