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Leica IIIg fast shutter speed dial anomaly


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I've just noticed that on my IIIg's fast shutter speed dial that on settings 1000 & B the dial sits higher than on the other settings ie it doesn't drop down as much ie there is a bigger gap between the baseplate & the bottom edge of the dial. Is that normal? It's going in for a CLA soon anyway.

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This should not be a problem, once the speeds operate correctly. A more common issue with LTM models is when the set speed numbers do not line up with the mark. I have a large number of LTM models and perhaps 3 or 4 of them do not fully line up. It is easy enough to fix by loosening the speed dial and moving it to the correct position using the 'Z' or 'B' setting and then re-tightening it.

 

William

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I've just noticed that on my IIIg's fast shutter speed dial that on settings 1000 & B the dial sits higher than on the other settings ie it doesn't drop down as much ie there is a bigger gap between the baseplate & the bottom edge of the dial. Is that normal? It's going in for a CLA soon anyway.

Do not worry! This is normal behaviour. Due to the tiny timing difference between 1/500 and 1/1000, the holes in the timing disk for these two exposures have to be very close to each other, so that the 1/1000 hole is more of a dimple or a hole with a smaller bore (otherwise there would have been overlap/confluence of the holes), that does not engage the dial‘s splint to the same depth as with the other exposure times.

 

(As a non-native speaker my technical terms are prone to be rubbish, I hope that I convey my point, nonetheless)

 

Kind regards

Mathias

Edited by schattenundlicht
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Do not worry! This is normal behaviour. Due to the tiny timing difference between 1/500 and 1/1000, the holes in the timing disk for these two exposures have to be very close to each other, so that the 1/1000 hole is more of a dimple or a hole with a smaller bore (otherwise there would have been overlap/confluence of the holes), that does not engage the dial‘s splint to the same depth as with the other exposure times.

 

(As a non-native speaker my technical terms are prone to be rubbish, I hope that I convey my point, nonetheless)

 

Kind regards

Mathias

Perfectly comprehensible

Cheers

Stephen

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My IIIg manual is in German - Ich spreche kein Deutsch!!

 

Hello Stephen,

 

If you go to the top of this page & click the "Wiki" and then go to "screw thread bodies" and then "click" IIIg and then go to the English language manual provided for us by Mike Butkus: You can read about how to use your IIIg.

 

Best Regards,

 

Michael

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Perfectly comprehensible

Cheers

Stephen

This line drawing does not represent the distances between the holes in a correct manner, but it clarifies the principle:

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[ Source: http://pentax-manuals.com/manuals/service/screw_mount_leicas.pdf ]

 

Whereas in this blow-up of a printed work details are less easy to discern, but it shows the real thing with the true spacing:

[ Since the above image is only a detail clipping of an illustration, I hope that posting it here will be deemed "fair use". The image is from the fantastic 1979 German language article by G. Mehlhose in Vidom #13, the title of which, freely translated, would be "The inner life of a Leica, and how to deal with it" ]

 

Kind regards

Mathias

Edited by schattenundlicht
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Although this thread has been cold for a few days, I would like to share some additional information on the reason why the 1/1000 sec setting leaves the exposure dial in a slightly elevated position in comparison to all other speeds:

 

a. The first reason, as has been stated before, is the proximity of 1/1000 and 1/500 on the timing disk, which would result in two full sized holes merging.

 

However, in later cameras there is an even more intricate reason:

 

b. The 1/1000 sports a seperate, more elevated post on the second curtain latch. Thus, the second curtain release lever, with the dial in elevated 1/1000 position, does not strike the ‚regular‘ post, but passes above it and strikes its generic own post, releasing the second curtain. All other exposures from 1/500 onwards set the second curtain release lever in the lower position, with the release lever thus striking the ‚regular‘ lower post on the second curtain latch.

 

Why this seeming over-engineering (well Leica is German, is it not?): Both strike posts are screwed onto the second curtain latch by eccentric.

 

Thus the very delicate timing of the difficult 1/1000 could be adjusted and fine-tuned seperately from the other exposure times...

 

Kind regards

Mathias

 

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Edited by schattenundlicht
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Apparently older Leica users like my father and grandfather were warned against using 1/1000th regularly as "it put too much strain on the mechanism". I believe this is rubbish and there is no more strain than any other speed. With 100 ISO being close to a "base" film speed now with only specialist films slower than this, if I want shallow DOF when using my LTM Summilux III, I end up using 1/1000th quite a lot of the time. 

 

Wilson

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Apparently older Leica users like my father and grandfather were warned against using 1/1000th regularly as "it put too much strain on the mechanism". I believe this is rubbish and there is no more strain than any other speed. With 100 ISO being close to a "base" film speed now with only specialist films slower than this, if I want shallow DOF when using my LTM Summilux III, I end up using 1/1000th quite a lot of the time.

 

Wilson

I would second your liberal use of the 1/1000 without any qualms.

 

Sometimes I do not find time to shoot for several days, thus I tend to load my cameras with ISO 400 film to be prepared for all the light that the weather may refrain from throwing at my camera. Thus I end up using 1/1000 quite a lot, too.

 

On a technical side: Either with the smaller hole close to the 1/500, or with the dual strike post version of the shutter timing mechanism, I cannot envision any undue stress that the 1/1000 would impose upon the mechanism.

 

The reason for it’s ill repute may have been that, because of the extremely small slit between the 1st and the 2nd curtain that travels across the film plane with 1/1000, any tiny maladjustment in one of the curtain spring tensions, any grit in the bearings, any misalignment of a curtain on a shutter drum, must have made the 1/1000 the most unreliable (or least reproducible) exposure time...

 

Kind regards

Mathias

Edited by schattenundlicht
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