dpullum Loc: Tampa Florida

Wow, yue-guyz really like to spend money and complicate things!! when less than $20 will solve the problem...
Syk‑5 Wireless Remote Flash...$11.99
Google syk-5 flash trigger

rmalarz Loc: Tempe, Arizona

At first, years ago, I used a Sunpak flash with my D700. It worked quite well. I don't remember the model number, but it was one of those potato masher style flashes.
--Bob

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

You can use a Wein "Safe Sync" to lower trigger voltages on shoe mounted units. I have any number of older shoe mount & potato masher units. Better to get a more current unit as the older units TTL aren't compatible with newer iTTL cameras. The pin configuration, while appearing the same, transmits different info & thus likely will not get triggered by the camera when you trigger the shutter. I have older (mid 80's) ring lights & when using the ones with a Nikon shoe, I have to tape over the extra pins in order for the flash to trigger. I also have ones with a "Standard" single pin foot that work fine as is... (No iTTl though, I shoot my macro images entirely in manual modes)

joer Loc: Colorado/Illinois

Nikon AS-15 comes with a small sync cord and mounts in the hot shoe.

Leitz Loc: Solms

My point was that no PC cord will connect directly to a hot shoe - some such adapter is needed.

agillot

from kd6sbn , with a voltmeter, turn the flash on , and measure the voltage between the 2 pins . i have 2 old flash , one has 5 volts [ so ok ] and the other 298 volts , so that one NO !

kb6kgx Loc: Simi Valley, CA

How do I know which are the two pins to check? There are, I think, five pins.

agillot

I WAS TALKING ABOUT OLD FLASH WITH THE 2 PIN / OR THE WIRE .in the case of a dedicated flash , i think you could just check the 5 pins in a random way to make sure you dont have high volt anywhere .the reason i like the 2 pin old flash is that on a nikon or ?? , it will flash no mater what at any speed when taking a picture , so if it has adjustable power level it make a great fill flash [ quantary Q 383 ], has 5 volt .

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Testing is done with the center pin (+) and the contact on the side of the shoe (-). Let the unit charge up fully first

amfoto1 Loc: San Jose, Calif. USA

The biggest concern using an old flash with a new camera is the trigger voltage of the flash.

Some old flashes used pretty high voltage. That wasn't a problem with the cameras of the day, but with modern electronically controlled cameras it became a real concern. More than a few modern cameras had their circuits fried by old flashes!

HOWEVER... some flashes never were a problem and in more recent years many (most? all?) camera manufacturers have "beefed up" their cameras' circuitry and components to be more tolerant of higher voltages.

The Sunpak 555 IS NOT a high voltage flash. It averages around 6V or less, which is quite low and even the worst-protected modern cameras should be able to tolerate it. (Some old flashes used upwards of 100V... some even, 250V or 400V!)

Here's a web page with user-tested and reported trigger voltage info for a whole lot of vintage flashes:

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

I have no idea the trigger voltage tolerance of the Nikon D7100 specifically... You can probably find out online with some searching. Maybe Nikon has info on their website or in some of their manuals. But I'm pretty confident it would be fine with the 555, because that particular flash uses such a low trigger voltage. (I shoot Canon and some of the late 1990s and early 2000s cameras' hot shoe rating dropped as low as 6V... but I think more recent Canon tolerate at least 24V and some are insulated to handle as much as 250V. That might only be with the PC socket, though... not the hot shoe.)

If you are at all concerned, triggering the flash with a radio device - as someone suggested - would isolate the flash from the camera to protect the camera (check the trigger voltage capacity of the radio device... though most have a fairly high safety margin).

There are also small protective devices that can be put between the flash and the camera's hot shoe, to insulate the camera from excessive trigger voltage. The Wein SafeSync is one that comes to mind. I'm sure there are others.

The Sunpak 555 is a good flash! It is basically a manual (thyristor) flash with "old school" dedication capability, by swapping out the flash's foot for different systems. If you were using yours on a Nikon film camera, it probably has the Nikon flash foot on it. There also was a "generic" non-dedicated flash foot available for the 555, which you may need to swap to, in order to use the flash on a modern camera and/or with any of the SafeSync devices or a radio trigger. I forget the model number of the generic, non-dedicated flash foot, but you can probably find one on certain auction sites for reasonable price.

You probably already know, "old school flash dedication" in the 1980s was little more than an extra circuit or two that might give in-viewfinder info when the flash was recharged and ready to shoot and/or might automatically shift the camera to it's flash sync shutter speed... but usually little more than that. And each camera manufacturer used different methodology, so they aren't very interchangeable. It's not capable of TTL metering or camera-menu control, the way modern flashes can be. So, you really don't lose much switching to a "generic" flash foot on the 555.

EDIT: I just looked up the 555 to refresh my memory and see that it uses the same "dedication" modules as many other Sunpak flashes. Yours probably has one of the "NE" modules for Nikon installed (since you mention using it on an older Nikon camera and that the flash foot has five pins). To use with modern cameras and/or any of the triggering devices, you should change that module to the STD-1D. With many Sunpak flashes the interchangeable module is part of the flash foot... However, with the handle-mounted 555 it works in conjunction with the EXT-11 Dedicated Extension Cord (which I'm guessing you already have).

Owners manual for the 555 is available online at:

http://www.cameramanuals.org/flashes_meters/sunpak_auto_555.pdf

It's free... though Mike Butkis is happy to accept donations in support of his efforts maintaining all those vintage manuals online.

OFF TOPIC: Did you know that you can make a homemade Taser from an old flash? Not that I'd recommend it... I imagine it would be VERY dangerous! However, this might suggest the voltages we're talking about with flashes, if they're capable of knocking someone on their arse!

kb6kgx Loc: Simi Valley, CA

I have a DVM at home. Will do that!

kb6kgx Loc: Simi Valley, CA

Decided to go for it, take a chance, and see what happens.

Manual mode. ISO 100. Set shutter to 1/250, aperture to f5.6 (manual lens: 50mm, f1.4 AI-S).

Pressed the button and... It seemed to work. Took two shots, images are s little on the dark side (will post them later). Not sure why. Flash at full power. Manual mode. About 5' or less from subject.

Screamin Scott Loc: Marshfield Wi, Baltimore Md, now Dallas Ga

Meant to say the flash foot, not the hot shoe...

kb6kgx Loc: Simi Valley, CA

I got that. In this case, the 555, being a "potato masher", the flash "foot" is actually attached to a synch cord which is plugged into the flas unit

romanticf16 Loc: Commerce Twp, MI

It should work in manual. The auto mode read reflections off the film plane, which a sensor camera is not calibrated to replicate.