Leica LTM LTM Leica slow speed dial position

Leica M39 screw mount bodies/lenses

biomadman

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I've recently read that when using higher shutter speed settings of a Leica III, the slow shutter speed must be set at 1/25 or 1/20. Similarly, it is also mentioned in the manuals of Canon V series and Nikon S2. Can anybody explain the reason why it is necessary to set the slow speed dial at the fast setting?
 
I've never heard from this. It isn't true. The slow speed knob of a Leica lll can be set at any time when using a high speed.

I haven't read it in the manual of the S2 either.

Erik.
 
I've recently read that when using higher shutter speed settings of a Leica III, the slow shutter speed must be set at 1/25 or 1/20. Similarly, it is also mentioned in the manuals of Canon V series and Nikon S2. Can anybody explain the reason why it is necessary to set the slow speed dial at the fast setting?


Not sure which Leica III model you have biomadman (and welcome to RFF). It's true for the IIIf. I am not sure why. Maybe something to do with engaging/disengaging the slow speed escapement?

This is how it is for the IIIf:

I always leave the slow speed dial on 1/25 or "25" (I have the IIIf Red Dial model) when using the faster shutter speeds. When using slower shutter speeds - I set the fast speed dial to 1/25 (or "25-1") and adjust the slow speed dial accordingly as per the manual...

I also found this interesting re: the slow shutter speed dial:

This range also covers speeds intermediate between those marked; thus, set half-way between ½ and 1 sec., the shutter yields an exposure of ¾ sec.
Intermediate speeds are not possible in the faster exposure range.

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I don´t have a IIIf, but do have all the other III´s. The high speeds of all of them work with the slow speed knob in any position.

Erik.
 
I have a red dial IIIf.....havent noticed this issue. However, from now on I'm going to make certain that I follow the manual. Does anyone have a IIIc manual?
 
I have a red dial IIIf.....havent noticed this issue. However, from now on I'm going to make certain that I follow the manual. Does anyone have a IIIc manual?

Yes it's the same requirement (1/20 or 1/30) for both the III and IIIc respectively:

(Leica III)
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(Leica IIIc)
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I never read an instruction manual to use my old Leica IIc, IIf, or my father's IIIf. But he taught me always to set the low speed shutter dial to the max speed when using the high speed shutter range. I presume that's what the people at Willoughby-Peerless told him when he bought the IIIf.

G
 
Yet another reason why the redesigned IIIc with its new body should have been called a IV but this is an unpopular view...

Regards, David
 
This is anew one on me and I've had a III for 50 years. All those pictures taken and I have no idea how the slow speed dial was set.

'The Leica Way' which I haven't looked at for years says:

To change from slow to fast speed simply change the setting of the main speed dial; the position of the slow speed dial is immaterial at any speed faster that 1/30 second, although this is not always the case with earlier models.

Hmmm
 
I think people over think this way too much. Using the top deck shutter speed dial the speeds go in a natural progression - 1/100, 1/50, 1/25 - unless the slow speed dial is set to some other value. The slow speed dial is intuitively used with the camera on a tripod. But it is possible to use the camera (when I was young and had nerves of steel) all the way down to 1/25th. But if I set the slow speed dial to a speed lower than 1/25th, say I/10th of a second or slower, and had set the main dial to 1/25th of a second it wasn't until much later I realized my mistake (usually when I developed my film). I don't think this has anything to do with the camera mechanics.

Bottom line is when the main dial says 1/25th don't you want the shutter speed to be 1/25th.
 
I don't believe returning the slow-speed dial to 1/20 - 1/25 - 1/30th or not for the faster speeds has that much influence on the selected exposure time. At least, I don't think I've ever paid much attention to it.

The only thing I can think of why this is mentioned in the manual is that the arm that links the slow speed escapement to the normal speed dial may need to be reset so that it possibly won't interfere with the release of the 2nd curtain as the shutter is fired.
 
For what it's worth, I just pulled my (black dial) IIIf off the shelf and played around with it for a bit. It doesn't seem to matter what the slow speed dial is set to if the regular shutter speed dial isn't set to 1/30; all the shutter speeds fire as if the slow speed dial is set to 1/30. I'd check with my IIIg, but that's currently loaded with film.

That said, I always make sure to lock the slow speed dial at 1/30 if I'm not using it anyway. Not because I think it'll do anything if it isn't set back to 1/30, but just because it's good to know where it's set so you don't get caught out if you don't check it.
 
Well, this has been bugging me so I had a go at it on a III, a IIIa and a IIIa syn.

If you set the camera to B (or Z) on the fast speed dial and the slow speed dial is not at its fastest speed then when you depress the shutter button the shutter opens but when you release the shutter button the slow speed mechanism will run for whatever exposure time it is set to before the shutter closes.

So, if you were doing a long exposure on B you might find yourself with an additional one second if the slow speed dial was set on one second.

This only happens when the fast speed dial is set to B (or Z) and does not apply to any other of the settings on the fast speed dial.
 
Wow thank you guys for all the information! After a month I would say I really agree with Dralowid. When you set the slow speed dial at any position but the highest speed, you will get the extra exposure time when using the B/Z mode. Other than that I cannot see any difference.
Well, this has been bugging me so I had a go at it on a III, a IIIa and a IIIa syn.

If you set the camera to B (or Z) on the fast speed dial and the slow speed dial is not at its fastest speed then when you depress the shutter button the shutter opens but when you release the shutter button the slow speed mechanism will run for whatever exposure time it is set to before the shutter closes.

So, if you were doing a long exposure on B you might find yourself with an additional one second if the slow speed dial was set on one second.

This only happens when the fast speed dial is set to B (or Z) and does not apply to any other of the settings on the fast speed dial.
 
This idea (and thread) pop up from time to time.

Thanks, @Dralowid for your testing!

The basic answer is actually in the instructions posted by @raydm6.

Paragraph 4:

"If it is desired to change from a long exposure to a short one, it is only necessary to adjust the dial 7 [main speed dial] accordingly, the position of dial 7a [the slow speed dial] being of no consequence. Only at 1/20 must both knobs be set at 20."

The italics are original. It is a question already old when the manual was written.
 
Back to my original post, you want to return the slow speed dial to match the slow speed dial on the top deck. Out shooting with my Nikon S2 today and I had forgot and left the slow speed setting to 1 second. So when I took a picture at 1/30 of a second imagin my surprise when the shutter didn't immediately close.
 
I have a IIIA, I shoot it without the leather case. I find myself accidentaly turning the slow speed knob to 8 when doing photowalks. I only noticed it after 2 to 4 frames of shooting. Then the some of the photos shot at 1/1000 has capping (darker on the right side). I have repaired this camera, replaced the curtains. Not sure if the capping is a result of the 1/8 position of the slow speed knob while using 1/1000sec, or maybe im still missing something after replacing the curtain. It is imposible to see the action of the curtain with slow speed installed since the shell should be installed as well. I thoroughly examine the sound of 1/1000sec with 1/8sec actitaved and i can hear a difference.
 
There may have been complaints to Leitz about running into the problem Mark had. I’ve done this more than once. It’s an operational admonition, rather than mechanical in the IIIf manual. German instructions tend to be more emphatic than English. We are likely seeing a literal translation. After shooting at 1/4 or 1/8 if you don’t return to 1/25s on the IIIf then the longer speed setting sits there to trap you next afternoon, or the one after, as the light fades and you look for more light by doubling the exposure from 1/50s to 1/25s. But instead of doubling the exposure you‘ve quadrupled the exposure or more for not having locked the slow speed dial back at 1/25s.
 
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