View single post by Robert
 Posted: Fri Jun 29th, 2012 02:42
Robert



Joined: Sun Apr 1st, 2012
Location: South Lakeland, UK
Posts: 4066
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PRSS, I wouldn't use either flashgun, despite Doug's assertion that the Nikon spec's say 250 Volts and your measurements giving 9 and 200 Volts respectively. Why?

1, The circuitry is old, and may be 'leaky', I will explain in 2.

2, In order for a flash to fire, a high voltage (between 1,000 and 4,000 Volts) is 'flashed' across the tube exciting the xenon gas inside which is then energised for as long as the flash gun settings allow it to create an intense light. You can liken this high voltage energiser to a spark in a cars engine.

If you look at the flash tube you will see it is slightly yellow, that is a gold coating which conducts the high energy charge over the tube to initiate the flash.

What you are measuring with your test probes is the battery charge level, like perhaps the cars battery which would be 12 Volts on most cars.

IF the flash guns's circuitry is 'leaky' then some of that high energy flash power which may be anything from 1,000 volts to 4,000 Volts, MAY find it's way to the camera.

Leaks can come from old diodes which can leak back some of the current they are switching, from bridging of tracks on the circuit board or resistors gone bad, any number of causes.

As I have said already, to me it isn't worth the risk. The only way you can measure it properly is with an oscilloscope by an experienced electronics engineer, which isn't worth the trouble.

A couple of links to explanations.

http://electronics.howstuffworks.com/camera-flash3.htm

http://caves.org.uk/flash/isolator/60_21.isolator.pdf

There are many others; Google.


I would have replied properly yesterday but when I tried to research my reply I had great difficulty remaining online because my new router appears faulty. Now using backup.


I don't wish to appear a killjoy, simply don't wish you to kill your camera by using these vintage flashguns connected directly to the camera. I am all for using vintage equipment, lenses, cameras, bellows I use a lot of old gear but not vintage flash connected directly to the camera. Especially when there is a workaround.

As it says on the website... Your call.



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Robert.