Copal 0 flash sync question

[James Westfall]

I have a newly acquired 90mm Super Angulon 90m/f8 on a Copal 0 shutter.

I was playing around with it last night using a pc sync cable to one of my remote flash Trigger (edit: I meant to type Trigger NOT Shutters). My understanding was that the flash sync switch should be set to X, rather than M.

During my 'testing' i noticed the flash did not consistently fire at each shutter speed when set to X. Out of curiosity, i switched to M and the flash fired at each speed.

Should I just accept this glitch and be happy I have a functional flash sync option, or is this indicative of a bigger problem?

Thanks for any and all replies.

PS. I'm still new to the board, so if this should have been posted elsewhere please feel free to move the post.

[Bob Salomon]

Get your shutter tested!

[Jim Jones]

In a properly working shutter, the M setting will not trigger an electronic flash at the correct time. It is for use with flash bulbs.

[Leigh]

I was playing around with it last night using a pc sync cable to one of my remote flash shutters.
What's a "remote flash shutter" ?

You need to explain the problem more exactly.
Does the flash always work at some speeds and not at others,
or does it sometimes work and sometimes not work at the same speed?

- Leigh

[Pere Casals]

My understanding was that the flash sync switch should be set to X, rather than M.

Yes, M position is for medium speed antique devices: after firing flash it delays the shutter aperture by (IIRC) 20milliseconds to allow the antique flash reach its peak power.

https://en.wikipedia.org/wiki/Flash_synchronization



During my 'testing' i noticed the flash did not consistently fire at each shutter speed when set to X. Out of curiosity, i switched to M and the flash fired at each speed.


This is because the "M" position perhaps it has never been used and it may retain some kind of noble metallic coating in the inner contacts, so still it has no oxide in the contacts, but it may have oxide in the future if you use it.

The problem is that present flashes source a very low voltage to the inner shutter contacts, compared to the antique systems, then this low voltage cannot break a thin oxide layer in the electric contact.

To avoid all problems, you can DIY an activation circuit powered with some 9v Battery, and this circuit would trigger your flash, I've done that, it's a quite simple circuit, but you have to DIY.

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If you are interested in that way but the posted schematic is not enough for you then please send me a PM and I would guide you in all that you would need.

[James Westfall]

What's a "remote flash shutter" ?

You need to explain the problem more exactly.
Does the flash always work at some speeds and not at others,
or does it sometimes work and sometimes not work at the same speed?

- Leigh

Sorry, i should have typed Trigger, not Shutter.
This isn't the one I have but it's something like this. I connected the cable to Copal shutter and then to the trigger. Then attached a receiver to a flash.
It worked on each shutter speed on the X setting from 1 sec to i think 1/40. On the M setting, it fired on each shutter speed.
I hope that clarified my original question.
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[Pere Casals]

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Y use the same remote triggers, if you take a tester you will find that a very low voltage is sourced to the contacts.

[Bob Salomon]

Sorry, i should have typed Trigger, not Shutter.
This isn't the one I have but it's something like this. I connected the cable to Copal shutter and then to the trigger. Then attached a receiver to a flash.
It worked on each shutter speed on the X setting from 1 sec to i think 1/40. On the M setting, it fired on each shutter speed.
I hope that clarified my original question.
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Do the instructions detail what shutter speeds will work at various distances? Is the trigger radio controlled or IR or a small flash unit?

[Pere Casals]

Do the instructions detail what shutter speeds will work at various distances? Is the trigger radio controlled or IR or a small flash unit?

Bob, this is RF. Those remotes work perfect with any DSLR, but they source a too small voltage to break the thin oxid layer on many LF shutters.

"The trigger voltages provided by some modern flashes or radio triggers can also be too low to reliably trigger electronic circuits in the camera or receiver. Trigger circuit voltages below ca. 2 to 2.5 volts may exhibit this problem, unless the triggering circuit is specifically designed to work with such low voltages." https://en.wikipedia.org/wiki/Hot_shoe

[Tobias Key]

I have two different flash triggers. One works with my LF shutters the other doesn't, so it varies from brand to brand. Personally I just use a good old fashioned sync cable because with the sort of outputs you use with LF typically, it's more than enough to trigger the optical slaves on other flashes.