PDA

View Full Version : PC port longevity impacted by wireless vs wired triggering?



feppe
6-Aug-2013, 12:42
My "new" Heliar had an unreliable PC port, and I had it fixed. When I picked it up from my local camera store, I was informed that using a cable to trigger the flash causes much more wear on the PC port than using the PC port to trigger a wireless trigger. Apparently voltages required to trigger via cable are higher. So, is a wireless trigger easier on the PC port than using a cable?

This is the second time I've had a PC port fail - first was tripping on a cable, second lens came with a faulty port -, and they're pretty expensive to get repaired, so I'd be interested to maximize longevity of the port. I've used wireless as a backup, and wired as my main trigger - if what he said is true I should switch the priority around.

David A. Goldfarb
6-Aug-2013, 12:53
If you have strobes with high-voltage output, you could put a Wein Safe-Sync or a wireless trigger between the strobe and the shutter to reduce the voltage that could cause arcing and cause the contacts in the shutter to deteriorate over time.

Sevo
6-Aug-2013, 13:38
The first electronic flashes were directly triggered by switching the ionizing voltage - often 240V rectified straight off the grid, which could cause arcing wear on the contacts (or kill careless photographers). These had a reputation for accidentally arc welding earlier (bulb) flash contacts shut. Shutters from the mid fifties on generally were built to stand even the extreme conditions of first generation electric flash. By the seventies, safety regulations mandated that trigger voltages had to be in regions not considered potentially lethal (i.e. less than 50V), and with the advent of digital circuits in cameras and flashes, triggers went further down to CMOS or TTL levels. Gradually, camera specs were loosened to follow these sinking voltage requirements. But up into the late eighties, just about every professionally used camera or shutter was at least 50V safe, and the majority could still stand the full 240V - it was not until digital that cameras were declared unsafe for trigger voltages above whatever computer internal levels the cameras used themselves.

However, the later developments above occurred in small format only - few LF shutters were designed so late that the makers could have disregarded backward compatibility to early seventies vintage large scale studio flash systems, and besides, even most "electronic" LF shutters are spring loaded mechanical shutters with a solenoid timer grafted on, and employ a mechanical trigger contact. I would not care to try ancient flashes on the rare few fully electronic LF shutters (part of the Sinar electronic shutters fall into that class, plus a few even more exotic ones), but apart from that, LF shutters are safe for just about any flash ever made.

feppe
6-Aug-2013, 16:26
The first electronic flashes were directly triggered by switching the ionizing voltage...

This is not about safety for the flashes, but the longevity of the PC port itself.

Sevo
6-Aug-2013, 23:39
This is not about safety for the flashes, but the longevity of the PC port itself.

Just what I said... The flashes obviously were fine with that - internally even every current flash triggers by applying a ionizing voltage along the tube. It was the cameras (and careless operators) that sometimes got damaged.

Leigh
7-Aug-2013, 00:21
There's a dramatic difference in the amount of current and arcing on a set of contacts if triggering a flash tube directly versus triggering a remote. The direct mode would cause much greater "wear" on the contact set.

Arcing is the main problem, as it causes pitting of the contact surface, which degrades its operation.

The remote receiver that triggers the flash experiences the same environment, but it uses an electronic component, not mechanical contacts. Solid state devices of this type are impervious to arcing.

- Leigh

Mark Barendt
7-Aug-2013, 04:11
It is actually the current/amperage that is the problem regardless of the voltage. Extension cords do need a bit more input current to get the required output, but the extra current has to be available to the circuit.

If you are using modern strobes/flashes then there is normally a very limited amount of current available in this circuit to worry about because this circuit is only designed to be and used as "a trigger" to turn on another switch (inside the strobe) that powers a separate very short "power circuit" that carries the main load of the lamp.

feppe
7-Aug-2013, 11:58
It is actually the current/amperage that is the problem regardless of the voltage. Extension cords do need a bit more input current to get the required output, but the extra current has to be available to the circuit.

If you are using modern strobes/flashes then there is normally a very limited amount of current available in this circuit to worry about because this circuit is only designed to be and used as "a trigger" to turn on another switch (inside the strobe) that powers a separate very short "power circuit" that carries the main load of the lamp.

I'm using modern Elinchrom lights, but would it be beneficial to move to wireless triggering to limit wear on the PC port?

It would make sense just from the point of view of eliminating the chance of tripping on the cable.

Leigh
7-Aug-2013, 12:02
I use PocketWizard II wireless triggers for my Elinchroms, and find they work flawlessly.

If you use a Sekonic combination meter like the L-558 you can also trigger those remotes directly from the meter.

- Leigh

Sevo
7-Aug-2013, 13:33
I'm using modern Elinchrom lights, but would it be beneficial to move to wireless triggering to limit wear on the PC port?

It would make sense just from the point of view of eliminating the chance of tripping on the cable.

The latter is a valid reason. You won't find a LF camera or shutter you can damage with the trigger current from a recent Elinchrom.

Harold_4074
14-Aug-2013, 11:25
It would make sense just from the point of view of eliminating the chance of tripping on the cable.

Oh, yes. I have a (faint) scar from the five-stitch suture right in the middle of my forehead, acquired when I carefully stepped over a sync cable and bumped into the corner of the camera stand arm. The next day, I ordered a set of PocketWizards, which actually cost less than the urgent care clinic work...