Vivitar 283 won't fire with 20D

[chiswick_john]

Either mounted on the hotshoe or via the PC socket - no flash.

[chiswick_john]

DOH! - C.Fn-07 - sorry.

[jimstrutz]

You did check the sync voltage, right?

 

http://www.botzilla.com/photo/G1strobe.html

[yat_tang]

Only E-TTL flash will work with digial EOS. Or you can use it in manual mode.

[jimstrutz]

Not quite Yat. You can also use "auto" on flash units like the Vivitar 283, Sunpak 383. In fact, using an autoflash unit on most Canon DSLRs isn't such a bad idea. Flash exposures are usually more reliably accurate than using E-TTL. A lot of DSLR owners have sold their EX series Speedlites and gone back to autoflash. However, with the 20D using E-TTL II, some people are reporting that flash exposures are much more accurate than before. Still, a 283 is a low cost way to get good flash images.

[Rob_L1664876404]

My old 283 measured at over 200v trigger voltage. If you didn't measure the trigger voltage first, you may have already fried circuitry in your 20D (max 6v).

[jimstrutz]

Hey, I just remembered that I read somewhere that the 20D is rated for 250 volts on both the hotshoe and PC terminal. Can anyone confirm?

[jonathan_laufersweiler]

That's more than 6, but I'm guessing that sgould still be within tolerances. Haven't

tried it on a digital yes. Any opinions?

[jimstrutz]

I've always held that anything less than 10 volts was perfectly safe with any Canon EOS. There are a lot of folks that have used flsah units with sync voltages marginally too high. In fact there are a lot of users with 20+ sync voltages, without any trouble. But.... Canon still states no more than 6 volts on most of their cameras.

 

There is an international standard for sync voltages on all new equipment that states that sync voltages should not be over 20 something volts. (I don't remember the exact figure.) Canon is a signer on that international standard. But... Canon still states no more than 6 volts on most of their cameras.

 

At least some of the EOS 1 series cameras are rated for 250 volts though.

 

BTW, this should be checked with a volt meter that has at least a 20,000 ohms per volt rating. Lower resistance (cheaper) voltmeters can draw down the real voltages on many of these flash units since their potential amperage is so low. This can result in an artificialy low reading.

 

All that to say, your 8 volt flash unit is probably perfetly safe to use on any EOS camera but mine. :0

 

Just kidding. I've used up to 12 volts a time or two.

[roger krueger]

Has it fired with other electronic sync sources? I've had not 1 but 2 different 283s that

would fire with mechanical sync sources, like my Mamiya Press or Minolta XD-11, but

refused to fire off an E-10 or any of a number of cheapie slaves that fired other 283s fine.

My guess is that the waveform wasn't quite steep enough, or the resistance was too high,

and it didn't generate a sufficient trigger pulse across the tube. They were both high-

voltage units, but I've had other high-voltage units work fine.

 

Also worth noting is that at least some 283s have a modest DC voltage but a high AC

voltage across sync--best to check it both ways. That said, I've used 200-volt 283s on

both an E-10 and Sony DSC-770 for extended periods of time with no ill effects. (although

99% on a bracket with a sync cord, not in the hot-shoe.) The E-10 specifically had several

thousand high-sync-voltage exposures before it was stolen.

 

The high-sync-voltage issue is mostly cover-your-butt specs from Canon combined with

general hysteria. The only reports I've seen of actual dead cameras were the first

generation of cheap TTL bodies from both Canon and Nikon. It seems the sync circuits

were safe, but if you twisted the flash wrong taking it off and the 200V hit one of the TTL

circuits it fried.