I have two Vivitar flash units the 273 and 2000, both were used on a film camera. If I use one of these units on my PENTAX K-x will it burn out the circuits? I read somewhere that if one uses a flash that was intended for SLR camera the voltage would be too high to use it on my K-x. Hopefully, you smart guys and gals may give me a simple answer.

David R.

[UncleVanya]

That’s a complicated question. Nowhere that I know of is an official answer from Pentax on the maximum safe voltage. Some sources claim Pentax engineers gave them fairly high voltages. It does appear Pentax is less sensitive than some other brands but there are precautions you should take.

1) you can use a safe sync device to isolate the camera from the flash.

2) you can use wireless triggers, either with the flash mounted directly into the trigger on top of the hot shoe camera or on another trigger off camera/remote. Off camera is certainly safest but only marginally more risk is added when used on top of a trigger on the hot shoe as long as it is voltage isolating. Most - not all - act like a safe sync. Do a little research if you want to use it that way.

3) you can look up what the trigger voltage is here: Photo Strobe Trigger Voltages. Based on that voltage you may be willing or unwilling to risk direct use on the hotshoe.

Read this also: Flash trigger voltage - PENTAX official answer - PentaxForums.com

My view is that those flashes are around 200v and I wouldn’t risk it without some isolation like a safe sync or a trigger. It is under the value one engineer said might be ok, but it is also old info and newer camera may not be that safe and the caveat in the reply isn’t very assuring.

[Gamblat]

Why chance it.

[wcs2229]

High probability that old Vivitar electronic flashes have high voltage at sync contacts. They are not valuable, so better to buy new equipment instead of risking.

[Photos-by-Chas]

I have two Vivitar flash units the 273 and 2000, both were used on a film camera. If I use one of these units on my PENTAX K-x will it burn out the circuits? I read somewhere that if one uses a flash that was intended for SLR camera the voltage would be too high to use it on my K-x. Hopefully, you smart guys and gals may give me a simple answer.
David R.

I have several flashes for film cameras; Focal M500, Vivitar SF-4000, two Quantaray QB-350A, and a Pentax AF-160Sa. I have used all of them on a Pentaxk K1000 SE (film) a Petri FT (film) and digitals Pentax istD, Pentax Kx and now on a Pentax K-70. I've had no problems with any camera or flash. Anecdotal evidence but maybe a good omen for you.

[Lord Lucan]

Vivitar flash units the 273 and 2000, both were used on a film camera. If I use one of these units on my PENTAX K-x will it burn out the circuits? I read somewhere that if one uses a flash that was intended for SLR camera the voltage would be too high

Both have a dangerous voltage : Photo Strobe Trigger Voltages

Vivitar 273 ~290v

Vivitar 2000 ~200v

It is not because there are from the film era. Later film cameras also had delicate electronics. Flash units intended for later SLR film cameras did have lower trigger voltages, typically around 6v. I have several flash units from the 1980s and 1990s which I use on my modern DSLR, but after checking the voltage is safe.

PS : Just noticed the OP was guest about 9 months ago! I guess he has either fried his camera or binned the flash units by now

[UncleVanya]

Anecdotal evidence is that Pentax dslr cameras have been - in the past at least - pretty tolerant of higher voltage trigger values. One quote from a Pentax tech suggested 300v was ok. Other quotes have suggested far lower. Other brands have more evidence of intolerance but safer to not risk.