Quick question

[David Hughes]

Hi,

I can't use my right hand properly at present and so I can only wonder what's under the screw with a slot for a coin on the top of the VACU thing. Has any one investigated? I'd do so if I could...

Regards, David

 

[VictorM.]

What's a VACU thing?

 

[David Hughes]

Hi,

Well, I hope it's one of these things:

It comes in several different varieties. It screws on to the back of the old screw thread camera and fires a flash gun. You have to change the shutter speed dial for a special one for your camera model. The new dial has a bump or cam on it. The cam fires off a contact as it goes round. All I know is that this might be one and that it's the version for electronic flash guns. What Leica model it's for escapes me and I know no way of telling without searching for a speed dial for all the Leica's I own and then converting the plug and then firing off a lot of test shots.

Here's the thing mounted on a IIIc:-

After taking the photograph I realised that I'd chosen the only IIIc in the heap that's got a 3mm flash plug fitted and - as you can see - has a special speed marked with a red dot on the dial. But the dial isn't the one with a cam to work the VACU...

Any comments or help with this irritation would be appreciated.

Regards, David

PS You'd think Leitz would mark it with the model it was meant for but, alas, they didn't.

PPS The screw thread around the shutter button on the VACU is for the shutter button guard from elderly Leicas. That also adds to the mystery as I'd not expect a version for electronic flash to be modelled around the pre-war ones. I'd expect it to be for the long bodied ones only. As I remember electronic flash guns became generally available/affordable in the early 50's.

 

[sevo]

I suppose the contact adjustment would be below there.

And the VACU will have preceded electronic flash, as it is named after a flash bulb: "Vacublitz" was a Osram trade mark for reduced pressure "non-exploding" flash bulbs that first were marketed in the early thirties.

X-sync preceded electronic flash by a couple of decades - it had been the original slow bulb sync scheme, the only one that did not need extra delay timers. The more complex M/F/FP timing schemes for fast or flat-peak brightness bulbs did not appear on cameras until the forties or even fifties, i.e. around the time when the first electronic flashes began to appear.