NikonRocks Loc: Sydney

I have purchased a new Nikon D500. This DSLR body has an external flash sync connector similar to what used to be standard on most brands of the older film SLR cameras of yesteryear. This connector on the older style cameras allowed for flash units and other types of strobes to be synchronously triggered when the shutter opened.

An electrical cord would connect the flash/strobe unit to this external connector on the camera either because the unit was off camera or the camera didn't support a hotshoe.

The older type of flash/strobe units when powered up would present a terminal voltage of 250 or more volts DC and the older cameras were able to accommodate such voltages and fire the unit without damage to the camera.

What is the situation with the D500? What is the rated maximum terminal voltage that this external flash sync port on this camera can support?

I have not been able to find this information documented in the supplied camera users manual or elsewhere. Do any of you hoggers know definitively what this voltage rating is?

Longshadow Loc: Audubon, PA, United States

If you can't find out, check this out to be safe:
https://www.bhphotovideo.com/c/search?Ntt=Safe%20Sync&N=0&InitialSearch=yes&sts=ma&Top+Nav-Search=

My camera can't handle a trigger voltage over 5-6 volts.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Nikon specifies a maximum trigger voltage of 200 VDC. Most modern flash equipment operates at a much lowe trigger voltage, however, especially if you are using older flash gear, it is wise to check out the voltage across the synchronization socket or at the foot that attaches to your hot shoe.

As a further precaution, with units of unknown trigger voltages, it is wise to use a
SAFE-SYCCH device which interphases between the synch cord and the terminal or the foot and the hot shoe.

These devices reduce the voltage to a safe level.

Attached is a few illustrations of how to prob the flash units with a voltmeter. There is also some images of the Safe-Synch. There is also a protective device made by Paramount Cords. The list of synch voltages is a good reference, but an old or possibly malfunctioning flash unit can harbor dangerous voltages... better to test!

tvhasben Loc: Chattanooga, Tennessee

Here's a link to show what the trigger voltages of a lot of older, classic strobes. Most newer strobes fall somewhere around 5 to 6 volts or less and some newer cameras allow up to 24 volts. The list is way old, but still very useful.

http://www.botzilla.com/photo/strobeVolts.html

NikonRocks Loc: Sydney

Thanks to all who have replied with useful information. I sent a query to Nikon technical support here in Australia and they promptly replied within a few hours as follows:-

"The Nikon Digital cameras worked slightly different from the older film cameras. The D500 as well as most other newer D-SLR, are all rated safe to a max 250V from the hot-shoe.

However, we can’t guarantee the use of 3rd party, or older equipment (Which is more likely to use high voltage) to the system, and as mentioned in user manual (page 197), not recommended.

This one is good site for a general understanding on these voltages - https://www.shutterbug.com/content/using-older-electronic-flash-digital-cameras-what-works%E2%80%94what-doesn%E2%80%99t".

So there we have it. 250VDC from the hotshoe. But they didn't mention the Flash Sync Terminal. Maybe it's rated the same. I'll get back to them and check. I don't want to leave anything to chance!

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Whether you have a flash unit mounted on the hot shoe or connect the flash to the camera's synchronization mechanism via the PC type socket, the issue of excessive
trigger voltage is the same. Always take precautions, especially with older flash gear or any unit of unknown or untested specifications.

It's not just a risk of carbonizing or burning out the internal synch contacts but causing serious damage to all the camera's circuitry.

Up to date speedlights that are dedicated to your camera will not pose any risk.

Manglesphoto Loc: 70 miles south of St.Louis

I am suggesting the obvious: just use a remote trigger!! no direct connection tour camera.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Then you have to check to see the maximum trigger voltage on the trigger. But replacing a trigger is preferable to repairing the camera.

olsonsview

A safe sync device would be wise to use. I have had some studio flashes read as high as 600V ! And by the way the voltage as measured by a meter may not be even close to accurate. An oscilloscope is a better tester according to engineering friends. The peak sync voltage spike may actually occur in too short of a time period to record on a meter. Worth spending a small amount to protect your camera.
No camera manufacturer will repair your camera for free if any voltage spike from a flash caused the problem.

BebuLamar

How do you measure the peak voltage of a flash sync circuit?

BebuLamar

To answer you question I am quite sure that that the voltage rating is the same for the hot shoe or the PC sync socket. So if it's not safe for the hot shoe it's not safe for the PC sync port.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

The OP did not specify the make and model of the flash gear he intends to use with his Nikon D series camera.

Some flash equipment, especially a few studio type units, harbor extremely high trigger voltages that can also damage the receiver or transceiver connected to its sync. terminal and can also damage the camera in certain transmitter/transceiver configurations.

MANUAL radio triggers, such as the simple POCKET WIZARD models can handle up to 300 VDC. The radio triggers that are designed to enable TTL functions tend to weigh in at substantially lower voltages and could sustain damage to the receiver that is connected to the offending flash unit.

In a configuration where the transmitter or transceiver is attached to the hot shoe or the PC terminal of the camera and also has a terminal that is directly connected to an on-camera flash unit, can damage the camera because the on-camera flash is NOT triggered by a radio signal but is a direct connection.

There are a few older makes and model of studio type flash equipment that has comparatively low trigger voltages because of a thyratron (vacuum tube) in its trigger circuit that acts as a relay or switch to effect synchronization at safe voltages. There is, however, an alternative connection in, some older models, that enables slave triggering, utilizing a simple plug-in photoelectric cell, that bypasses the thyratron circuitry and triggers at as much as 300 VDC. and unfortunately, this connection is accessible through a plug-in cord . Older model Photogenic Flashmaster, Starlighter and some Ascor units have this issue. Some older Vivitar speedlights and a few older Sunpack models have crazy high trigger voltages.

These are some of the reasons why I always advise testing and use of a Safe-Synch adapter, especially if I don't know the make, model, condition, and age of the flash equipment in use. There are some folks that claim that all this camer damage potential are urban legends, rumors and old wives tales. Well, if you over-volt you camera's synchronization mechanism, it won't explode, burn up in a fireball or kill the photograher. As folks euphemize about a dearly departed beloved pet- it will peacefully "crossover the rainbow bridge".

GoofyNewfie Loc: Kansas City

BTW, this is called the PC connector or terminal (PC=Prontor-Compur}

nadelewitz Loc: Ithaca NY

With the flash on and fully charged you measure the voltage across the main center terminal of the flash shoe and the ground terminal, which is a springy metal thing in the side slot that slides onto the camera hot shoe. Preferably with a digital voltmeter. Or if it does not have a hot shoe, measure across the outer ring and center pin of the synch cord.

williejoha

I would screw around with it. Most newer electronics are very very sensitive to over voltage. Your call.
WJH