High flash trigger voltages and vintage cameras w/wo metering circuitry

[StanMac]

I have several 60s and 70s era film cameras, some with metering, some without and some with hotshoes and some without. I am in need of flash units for use on these cameras but am concerned about buying one that may fry my camera, it's wiring for flash sync, or the metering circuitry. I've read some inquiries on various sites about using high trigger voltage flash units on newer SLRs and even digital cameras, but I'm curious about the effect of high trigger voltages on manual cameras with no or minimal electronics, e.g., metering circuitry. Is the flash trigger voltage an issue with these older, mechanical cameras?

 

[Moto-Uno]

^In a word NO , however the "Secrets of Powershot" website has lots more info on this subject . Peter

 

[Robert Lai]

In these older cameras, flash synch consists of a mechanical electrical contact which is physically pushed by some cams on the shutter mechanism to close the circuit. The ancient flash units sometimes put very high voltages onto these contacts, leading to arcing. Back in the 1970s and 80s, I remember camera magazine articles claiming that if your flash synch is not working reliably, just fire off a few flashes. The arcing will "clean" your contacts.

I presume that the arcing will "clean" your digital and electronic film cameras also, so that they instantly die.

Since there is no harm in using the modern low trigger voltage flash units on these old cameras, I would recommend that you stay with the modern flash units.

 

[StanMac]

Thanks for your information, gentlemen. I rarely use a flash with my film cameras and if I do I don't need a lot of reach, so I'm wanting a small unit of a size similar to a Yashica CS-140 I purchased recently but which has a PC sync cord feature. The problem is that I can't find any small/compact modern flash units that have a PC cord feature for use on my vintage cameras that have no hotshoe. Even if it's possible to open one of these newer flash units up and wire in a PC cord, that is something for which I lack the expertise nor do I want to pay megabucks to get it done by a photo service that would be willing to tackle such a custom job. I guess I'll just keep searching until I find a low voltage unit with a PC cord. Surely some low voltage units units were made back in the day that used a PC sync cord and that may still be operational. Wish me luck!

I have thought of using one of those small Manfrotto LED light bars when I need light in a dim environment, but they look as though they would be really obtrusive when mounted and worse when they are lit (way bright, I bet)

Thanks again!

 

[madNbad]

There are adapters that have a hot shoe connection with a PC cord. Slide the adapter into the accessory shoe on the camera, plug in the cord to the PC socket, slide in the flash and you're set.

 

[Robert Lai]

Any of the small Nikon SB flash units will be safe, and they have a cable that plugs into the side for a PC cord. I use an SB-7 (F and F2 shoe), handheld with the PC cord. SB-8 uses the standard flash shoe, but the contact may short if you put it into a cold accessory shoe in the camera. When you plug in the PC cord, the hot shoe is disabled, to prevent this from happening 😎
These cost about $20 or less, on the 'bay.

Vivitar 285HV is much larger, but offers a PC cord option also. The supplied cord is very short, but longer coiled ones are available from Paramount cords.

 

[Dwig]

...I'm curious about the effect of high trigger voltages on manual cameras with no or minimal electronics, e.g., metering circuitry. Is the flash trigger voltage an issue with these older, mechanical cameras?

First off, camera electronics and metering circuitry have absolutely nothing to do with the issue of damage from high trigger voltage flashes, at least directly. The issue with cameras being damaged by high trigger voltage revolves around bodies that have extra flash contacts to communicate with "dedicated" flashes. That extra communication is usually to sense that the flash is ready and react to it (light ready light in VF, set the proper sync speed, ...) and sometimes to do TTL flash metering (sensor in body acts as a remote auto sensor for the flash). On such bodies, a high voltage brought in contact with the extra contacts in the flash shoe can fry the body's circuits. This can happen when a flash is powered up and recycled before mounting it in a hot shoe and the center contact (flash trigger contact) brushes across the extra contacts. As a rule, no extra contacts = no such problems.

Bodies without the extra "dedicated" contacts generally don't have such issues (I know of none). There are a few bodies that used switching electronics instead of a simple mechanical switch to trigger the flash (Olympus OM-2). These can have issues even when using a PC cord.

In my decades of selling and servicing cameras I encountered almost no cameras every injured by high trigger voltage flashes other than bodies designed for "dedicated" flashes. The few mechanical switched bodies where injury occurred involved "burnt" contacts (caused by arcing) that needed simply cleaning. There were generally cameras that were used extensively with high power studio flashes. Those that had issues were generally very old bodies or view camera shutters that didn't have gold plated contacts.

The modern "dedicated" flash bodies that died as a result of high trigger voltage flashes were dominantly Canon models, beginning with the AE-1. I never encountered a proven case of a Nikon or Olympus having a problem. Nikons have better designed shoe contacts and internal circuit protection.

The only issue I saw with any frequency with Olympus was with OM-2 bodies that would fail to trigger a HV flash due to a weak meter battery in the camera. These would fail to trigger the flash even when the aging battery still tested OK and still provided adequate power to operate the body's meter and shutter. Olympus' own dedicated flashes would still trigger OK because of their more sensitive low voltage trigger circuitry. I fresh battery would fix the issue.

 

[Roger Hicks]

First off, camera electronics and metering circuitry have absolutely nothing to do with the issue of damage from high trigger voltage flashes, at least directly. The issue with cameras being damaged by high trigger voltage revolves around bodies that have extra flash contacts to communicate with "dedicated" flashes. That extra communication is usually to sense that the flash is ready and react to it (light ready light in VF, set the proper sync speed, ...) and sometimes to do TTL flash metering (sensor in body acts as a remote auto sensor for the flash). On such bodies, a high voltage brought in contact with the extra contacts in the flash shoe can fry the body's circuits. This can happen when a flash is powered up and recycled before mounting it in a hot shoe and the center contact (flash trigger contact) brushes across the extra contacts. As a rule, no extra contacts = no such problems.

Bodies without the extra "dedicated" contacts generally don't have such issues (I know of none). There are a few bodies that used switching electronics instead of a simple mechanical switch to trigger the flash (Olympus OM-2). These can have issues even when using a PC cord.

In my decades of selling and servicing cameras I encountered almost no cameras every injured by high trigger voltage flashes other than bodies designed for "dedicated" flashes. The few mechanical switched bodies where injury occurred involved "burnt" contacts (caused by arcing) that needed simply cleaning. There were generally cameras that were used extensively with high power studio flashes. Those that had issues were generally very old bodies or view camera shutters that didn't have gold plated contacts.

The modern "dedicated" flash bodies that died as a result of high trigger voltage flashes were dominantly Canon models, beginning with the AE-1. I never encountered a proven case of a Nikon or Olympus having a problem. Nikons have better designed shoe contacts and internal circuit protection.

The only issue I saw with any frequency with Olympus was with OM-2 bodies that would fail to trigger a HV flash due to a weak meter battery in the camera. These would fail to trigger the flash even when the aging battery still tested OK and still provided adequate power to operate the body's meter and shutter. Olympus' own dedicated flashes would still trigger OK because of their more sensitive low voltage trigger circuitry. I fresh battery would fix the issue.

This is fascinating, reassuring and logical -- but is it universally true? So far I have hesitated to use my (30-year-old) Buff White Lightning flashes with my my Nikon Df, which has a proper flash synch nipple. Can you point me to someone who has tried it? I'm not calling you a liar: I'd just hate to fry my Df.

Cheers,

R.

 

[sevo]

This is fascinating, reassuring and logical -- but is it universally true? So far I have hesitated to use my (30-year-old) Buff White Lightning flashes with my my Nikon Df, which has a proper flash synch nipple. Can you point me to someone who has tried it? I'm not calling you a liar: I'd just hate to fry my Df.

I'd be very cautious there - none of the (arguably low end consumer) digital Nikons I have taken apart had a separate mechanical sync contact in the shutter. And YMMV as to what voltage a electronic switch can handle - unless the camera has an extra circuit that uncouples the trigger voltage from its electronics, it will be killed by some voltage only slightly above 3-16V.

 

[Dwig]

This is fascinating, reassuring and logical -- but is it universally true? So far I have hesitated to use my (30-year-old) Buff White Lightning flashes with my my Nikon Df, which has a proper flash synch nipple. Can you point me to someone who has tried it? I'm not calling you a liar: I'd just hate to fry my Df.

Cheers,

R.

I both did at the time and do now recommend caution and to not use high trigger voltage flashes with any camera body that supports a dedicated flash and/or has a fully electronically controlled shutter system. Today's digital cameras will almost universally be using some form of electronic "switch" to trigger the flash instead of the classic simple mechanical contacts. How well protected such circuits are will likely vary from camera to camera.

 

[ColSebastianMoran]

I would not use high-voltage flash on any modern camera.

If in doubt, these Wein SafeSync devices will protect your camera.

This table has info on the trigger circuit voltage for many legacy flash units. For example, some Visitor 283 units are several hundred volts.