Mystery German shutter?

[gma]

I recently purchased an old shutter that mounts on the front of LF lenses with a maximum barrel diameter of 49 mm The shutter has no markings to indicate manufacturer or country of origin. It has three positions - O, M and Z. O is open for focusing, M is a single speed of 1/50 to 1/100 sec (instant) and Z holds open while depressed for time exposures (as B). My Exakta model I in addition to B has Z for the setting that would be T in the U.S. Can one of the multilingual European photographers tell me what the German words are for O, M and Z ? I am curious. :?

 

[David A. Goldfarb]

Z is usually Zeit (Time). M is "Moment" I believe, or the "instantaneous" setting. O might be "Offen" for "open"?

I have a shutter like this, also no name, for lenses up to about 4 inches around. I use it on my big 360/4.5 Heliar, which happens also to be my avatar.

A company called "Luc" made a shutter like this, so that might be the manufacturer.

 

[gma]

Thanks, David. I want to use this with a variety of lenses. I think it will be perfect to use with short focal length lenses for macro work with 4x5.

 

[Seele]

GMA,

I happen to have a number of these shutters; before WWII they were generally called "Luc" shutters. After the war, in my old country (UK), Thomas Day of Twickenham sold a huge variety of them, for fitting in front of lenses, behind them, inside lens panels, etc. One that I particularly like is for fitting in front of a lens panel, with a universal lens holder at the front, which looks like a particularly sturdy iris diaphragm: you put your lens into the aperture, turn the ring, and the iris closes down to grip the lens and centres it automatically, and the shutter does its job behind it.

Back then, Thomas Day supplied an air valve for regulating speeds in these shutters, which came in two models. I can only give you the details from the British Journal of Photography Almanac, details from the previous year of course:

In the 1952 edition, the Thomas Day valve was reviewed and advertised without illustration, and in the next edition, it was illustrated: it is a small cylindrical thing with a little dial, in line with the pneumatic release tube, and the model which came out a year later is rectangular and larger. In its advertisments Thomas Day stated that the system was submitted to the National Physics Laboratory and was found that the shutter speeds delivered by the valve system was within 2-1/2% of the rated speed. I would not mind getting my hand on one of them at all!

 

[gma]

The shutter I have has three screws that are used to attach to the barrel. It uses a conventional release cable. The air valve option sounds like a good method to have multiple speeds. I expect to use mostly for macro photos with time exposures and I will not require accurate shutter speeds. Thanks for the info.

 

[Seele]

GMA,

Some models of this shutter have dual-release options: the same socket can either take a standard cable release or a tube for pneumatic release, it is easy to see though; if there is a cylinder to which the release is attached then it should be dual release compatible. Be sure that when you push the plunger of your cable release all the way in, the emerging wire correctly triggers the mechanism, for some cable releases I have tried, they either do not stick out enough to allow the blades to pass the point of maximum opening, thus making them unable to snap shut again, making the Instantaneous setting more like a Bulb; on the other hand, some other cable releases I have tried have the wire stick out too much, making it kind of caught inside the works.