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12-31-2014, 02:06 PM   #31
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When in doubt, measure the voltage between the center pin and the ground (the shoe or a contact on the shoe). I always measure an unknown new flash's trigger voltage. Turn on the flash, measure from the big center pin to ground. If greater than 6V, don't expose your camera to it. There is no point in risking a several hundred dollar camera in order to use an old flash. BTW The current product called a Vivitar DF 283 is a totally different beast. It has the Vivitar 283 name only, but is a recent, digital flash with no problem on the trigger voltage. It is a good flash for the money.

The early Vivitar 283s did have high voltage on the trigger, about 270v or more. They were meant to be triggered by a mechanical switch, so it was a non issue. After blowing up a few cameras with low voltage trigger capability only, Vivitar modified the trigger voltage to below 6v. Measure yours to tell. If you have one with HV trigger, I suppose you can use optical slave trigger or a Wein Safe Sync, but that seems like money down a rat hole. If you really want to use the old flash, build a safety circuit like this into the flash:

http://repairfaq.cis.upenn.edu/sam/zpaofu1.pdf

I still see old 283s used, because they have monster output. They used a huge storage cap and higher than safe voltage, but the result was very high output. Studio pro's use these on remote optical triggers for distributed lighting, good bang for the buck. I wonder how many radio triggers got blown up before people started testing the trigger voltage.

01-01-2015, 05:04 PM   #32
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Well, it's easy enough to check the unit with a volt meter, I can probably go down to Radio Shack and use one. Thanks for the info on the 622. I have one and like it a lot.
01-04-2015, 11:50 PM   #33
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@Wildlifephotog:
Just got my Vivitar 285HV. The unit was made in Japan, but clearly says HV. Does where it was made make any difference?
01-05-2015, 07:40 AM   #34
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The 285HV has a max voltage of 12 volts. That is safe for Pentax digital cameras.

01-05-2015, 11:14 PM   #35
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Thank you.
01-06-2015, 12:28 PM   #36
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This is as "official" as you can get, from any camera maker.

From Ricoh GXR Body User Guide.
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01-09-2015, 08:29 PM   #37
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@wildlifephotog & Not a Number:
I just bought a digital volt meter from Radio Shack and tested both my 285s, one being an HV and the other a non-HV. I set the meter on DCV and 500v but didn't get a reading; I set it to 200v and neither gave me a reading of than 5.6 on BOTH units. That confirms the 285HV is safe, but that also my 285 is safe as well, according to the meter. I will take wildlifephotog's word on the Sunpak 622, especially since if I were to use that, I would only be using the PC cord to go into the PC connection of my K-5 which is said to have HV protection, but that should be moot anyway.

The only question that remains for me is if my original 285 that I bought way back in 1984 will work, so when I locate that (haven't used it since I had my K10D), I'll test that too.

Thanks again to you both for such good advice.

01-10-2015, 11:32 AM   #38
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Some of the later 285's did have a low trigger voltage. But it is best to always test. There is no way to tell by just looking. Always error on the side of caution.
01-10-2015, 02:44 PM   #39
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QuoteOriginally posted by LXNights Quote
if my original 285 that I bought way back in 1984 will work,
I bought 285 in 1982-83. I don't remember exactly. I might have the receipt or warranty card somewhere. It tests out a 5.35 volts with fully charged NiMH (Eneloop) batteries. I bought my Minolta X-700 new in 1982 with the 280PX flash. The 360PX hadn't been released yet (and was going to be more than I wanted to spend on a flash). I needed more power so I bought the Vivitar 285.
01-10-2015, 04:06 PM   #40
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I have three 285's. One is 360 volts, second is 275 volts and the third is 5.5 volts.
My two 285HV's are both 12 volts. And all these are with fresh charged Eneloops.

A friend of mine has a 285 that spikes at 500 volts! He actually spot welded the contacts in a Zorki with it.
01-11-2015, 10:25 PM   #41
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I did test mine, both came out no higher than 5.6. Thanks again to both of you for the help. Like I said, I bought the volt meter so I will always keep a close eye on them.
12-14-2015, 04:16 PM   #42
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I got a Vivitar 285 recently, and it varies from 8.30 - 8.75 volts. It was made in Japan and the serial number is 7253864
12-19-2015, 08:35 PM   #43
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I recently got a volt meter and measured both a Vivitar 285 and the ironically named Vivitar 285HV, and both came in the safe zone for my K-3, K-50, and K-30. The K-5 has got hot shoe issues of its own but that's for another thread.
12-29-2015, 09:03 AM   #44
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I still like my old Sunpak Auto322 from my days of film work in my Pentax MX. But now that I found high trigger voltage could fry my just bought K20D, I checked the voltage at the hotshoe contacts and got a range of 175 to 179 volts. So now I'll only use the old 322 via the PC port on a flash bracket. But given the advances of wireless tech I'll upgrade to new tech that allows me to remote fire a new flash off the camera if i want.
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