I've read from many sources that film flashguns won't work with newer digital cameras due to voltage differences and timing differences (and trying may in fact damage my camera), however I have heard of people getting around this by using inexpensive remote flash triggers.

I have a couple of old film flashes lying around and I wanted to experiment with some off-camera flash - I've found this wireless remote but I wasn't sure if it would work with my older flash gun.

  • 1
    \$\begingroup\$ What camera and flash do you have? It may be the case that they are compatible. \$\endgroup\$ Dec 29, 2010 at 12:40
  • \$\begingroup\$ The Camera is a Canon EOS 500D, and the flash is a Yashica CS-250AF \$\endgroup\$
    – Justin
    Dec 29, 2010 at 13:54
  • \$\begingroup\$ I have been using an old Miranda 930TCD with cowboy studio radio triggers with great success. The site lists an output trigger voltage of 6.5 (I think?) volts. but as it is not on the camera hot shoe there is IMHO no danger. At best it could fry the triggers, but hey, they were dirt cheap. AND it has not fried one yet, I have been using for 7 months. \$\endgroup\$
    – user24587
    Dec 9, 2013 at 1:42

3 Answers 3


Make sure to look for the flash on the Botzilla list of strobe voltage, which has been around for a long time and is very well known (within the specific circle of peopel who care about such things. Or you can measure the voltage yourself. If that's no good, the same site has the info you want on slave triggers.


This article will answer most of your questions:


It also lists sync voltage limits for most cameras, brand by brand. To summarize from that article:

  • Canon (350D and later models): 250V (Chuck Westfall)
  • Nikon 250V (it's in the manual)
  • Olympus 24V?
  • Panasonic 15V?
  • Pentax 25V
  • Sony 24V?

The questions marks come in where more than one number is given, and the lowest one is taken to be on the safe side.

Then, measure your flash's sync voltage. You can look it up, but some models, like the Vivitar 283 and 285 can vary widely over the course of production. Some vintage 283s go up to 350V, some are in the <10V range.

I also wouldn't take the advice that any wireless trigger will work like a Wein Safe Sync. Some might. But wireless triggers, like camera hothsoes, also have a sync voltage limit. The Cactus V5 and Yongnuo RF-603II, for example, have a 300V limit. The Yongnou RF-602 and RF-603, otoh, have a 12V limit (hence the RF-603II).

You will also want to pay attention to polarity as well as the voltage.



When faced with an old but working flash offered to you, and wondering whether to risk acquiring it (possibly to find out it is a true high voltage model), there is a quick test that often (not always!) gives you a hint about the kind of triggering circuit used:

High voltage designs USUALLY allow triggering (also via the test button) with the unit charged but turned off.

Designs with a low voltage (6-30V range) trigger circuit USUALLY do not. One notable exception: All Metz 45CT-1 variants (some are high voltage, some not) do.

Also, anything using an SCA300/3000 style foot (eg some Metz, Braun, Osram units) tends to be in the 6-24V range.

There are exceptions, and safety for a given camera can only decisively be found out by measuring.

Note that for some cameras, everything above 6V or even 3.3V is out of spec and unsafe.

YMMV, but the cheap kind of radio triggers, specced to 12V, often handles 24V fine (and at $5-10 a receiver you can risk it. Mind that some need a MINIMUM distance between sender and receiver!). Not surprising - there are not that many electronic components/circuits (excepting such that need a 12V supply too) that, under low current situations, can switch 12V to ground but will die from 24V. Most IC logic level outputs cannot handle 12V, while there are not many discrete transistors/thyristors that cannot handle 24V. Specifications of 3.3V, 5V, or 6V however do sound like IC outputs directly wired to the hotshoe - 12V would damage them.

Note: When handling a found flash unit of completely unknown history, it is wise to let it charge for at least a cigarette's length or two before attempting to trigger it. This will allow the capacitor to re-form a bit. Supervise it, and obviously turn it off and put it in a non-flammable place if there is any smoke except that from the cigarette. If you want to be extra careful, use partially run down alkaline batteries or a current limited lab power supply.

Obviously, really refrain from attempting to disassemble these things, especially when charged - they are cramped and illogically built inside, things can unexpectedly fall into your hands or conductive objects, and there is enough energy stored in the capacitor (and often plainly accessible once the case is off) to a) make you a doctor or coroners concern if you get shocked by it, b) make your ears ring if you accidentally create a short circuit with a tool...


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.