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01-20-2018, 08:51 AM   #1
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Vivitar 285HV Zoom Thyristor on Pentax K-50


I have an old version Vivitar 285HV Zoom Thyristor (I know is old as I got it used from someone who was selling his father's camera accessories - $25 about 8 years ago).

I've barely used it since my film photography is done mostly outdoors on daylight.

I wonder, can I use this on my k-50 or is it going to fry it up?

Any suggestions where to look for this info? Vivitar has info on the newer 285 versions (DSLR safe apparently). I just do not want to fry up my dslr...

01-20-2018, 09:39 AM - 1 Like   #2
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Try this....
Photo Strobe Trigger Voltages

Would seem to indicate you will be fine to use the flash,

I have used this table with old flashes and have not fried my K5 or K3 or K30
01-20-2018, 09:40 AM - 1 Like   #3
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Do a search for vivitar 285HV trigger voltage. One link that came up was A Concise Guide to the Vivitar 285 and Vivitar 285 HV and Cactus KF36 with an explanation how to measure. If you want to play it safe anyway, use a Wein SafeSync.
01-21-2018, 12:35 AM - 1 Like   #4
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My advice is, don't bother. These Vivitars, despite being very popular, are actually miserable to use, with poor ergonomics. In film days, we needed to select an anticipated distance range for the subject, choosing a color code on the side dial, and then set the front dial to that color. EVERY other 3rd party flash, from Metz to Rollei to Sunpak, had a better control interface. Even today, working Strobist-style (non-dedicated flash, chimp and adjust) is much easier done with one of the cheap new Chinese flashes. My Youngyu flash has large, easy to read buttons and controls, and it benefits from 30 years electronic progress since the Vivitars ruled the Earth.

The best and safest use for your old Vivitar would be to attach a slave trigger and use it for remote lighting, as a second flash.

01-21-2018, 11:15 AM   #5
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Thanks for the replies.

Did some checking.

Mine is NOT the HV version, but plain 285.

Also DC volt measured (when charged ready to shoot) = 7.45 volts.

I do not think I will risk it. I do have a few film cameras with which I can use this dinosaur.
01-21-2018, 02:34 PM - 1 Like   #6
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QuoteOriginally posted by edom31 Quote
Also DC volt measured (when charged ready to shoot) = 7.45 volts.

I do not think I will risk it. I do have a few film cameras with which I can use this dinosaur.
The 7.45V is probably safe. (My Pentax AF280T measures 7.2V and is safe on my K-3.) As for the dinosaur label, it all depends on what one wants. At the very least your 285 can function as a powerful, focusable speedlight. I happen to be fond of so-called auto-thrysitor flash automation. It simply works and does so without the quirks of the various flavors of TTL flash. Your flash supports a distance range in Auto from 2-60 ft. and that ain't bad.

Have fun with it on your film cameras. I am confident you will be pleased.


Last edited by stevebrot; 01-21-2018 at 02:41 PM.

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