When did shutter speeds move from 1/25, 1/50, etc.. to 1/30, 1/60...?

I suspect that the change started with the introduction of the new Synchro-Compur with LVS and speed-aperture coupling. This shutter appeared in the Retina IIIc/IIc/etc in 1954.

Huss said:

there are people who insist on the importance of 'exactly right' exposures,

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Even for slide film, the difference between 1/25 and 1/30 is almost negligible -- 40 ms vs. 33 ms, that's about 1/2 stop if both are 100% accurate (and they never will be, with mechanical shutters). Same is true of 50 vs. 60, etc. About 25% difference, if they're perfect.

If you deal in milliseconds, then 1, 2, 4, 8, 16, 32 are 1/1000, 1/500, 1/250, 1/125, and 1/60, well within the accuracy of a mechanical shutter. Then 64 = 1/16 or so, 128 =~ 1/8, 256 ~1/4, and 512 ms = 1/2, near enough. I suspect this was given as the reason for the switch -- better maintenance of 1 stop increments.

Huss said:

Yup, same on my recent M3 DS. My M3 SS has the current speed settings.

It is interesting though that there are people who insist on the importance of 'exactly right' exposures, even though in reality that is purely hypothetical.
Because trying to transfer those settings to your camera, does not mean that will be those exact settings. Either by not having those settings, or the fact that, for example, 1.8 on your lens may actually be 1.9 or 2.1, or 1/250 on your shutter speed dial may actually be 1/190 etc.
And that's not even taking into account vagaries in film processing!

It's amazing we get any images at all!

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Mine is very early 55 or late 54, no frameline preview.

So if we're talking when Leica made the change, that puts it somewhere after 55 and between 55 and 58, which is when I think they went to SS. Ken Rockwell claims it was 1957 that leica changed the speed dial.

I hope that adds to the topic at hand.

And I know it was sarcasm, but it is amazing I get any images at all. My camera is nearly 70 years old. So is one of my lenses, a lovely collapsible 5cm from 1955. I think that's pretty cool.

I wonder if the progression on the No. 0 Compur was changed before that on the No. 1 Compur. I have a Schneider lens brochure with a date code of (probably) 1970. It shows a 180 mm Symmar in a No. 1 Compur, speed setting ring is that fine saw-tooth edge sort, progression is 1, 1/2, 1/5, 1/10 ... Also shown is a 90 mm f/5.6 Super Angulon in a No. 0 Compur, this has that newer style "blocky edged" speed setting ring and the progression seen is 1, 1/2, 1/4, 1/8....

David

Moose22 said:

Looking at my M3 right now.

5 - 10 - 25 - 50 - 100 - 250 - 500 - 1000

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I have a M3 and M2 with "modern" speed settings. I suspect that later bodies have the change?? Early M3s had glass pressure plates, changes happened I'm not an expert, that's for certain.

As said I put that change at about 1954. Thus I am surprised learning here about west-german cameras produced years later with still the old times-series.

And that Gossen gave up on the old times-series scale, and instead at otherwise same meter rather showed two scales of the modern series indicated that at amateur cameras in use the new series dominated within a few years.

Then there's this: My Weston Master IV has the following fractional shutter speeds marked: 1/2, 1/5, 1/10, 1/25, 1/100 and then the next speed is 1/250 followed by 1/1000. Intermediate shutter speeds in 1/3 stop equivalents are indicated by unmarked "blocks." In what looks like a concession to the newer shutter speed progression, the unmarked blocks corresponding to 1/30, 1/60 and 1/125 are red (but not the ones corresponding to 1/4, 1/8 or 1/15). General consensus from a cursory internet search shows the the Master IV was introduced in 1960 and presumably discontinued with the introduction of the Master V, which...

Depending on which website you believe, the Master V was introduced either in 1963 or 1964. On my Master V all the fractional shutter speeds in 1/3 stop equivalents are written out, well except for the one between 1/2 and 1/3, thusly: 1/2, (blank), 1/3, 1/4, 1/5, 1/6, 1/8, 1/10, 1/12, 1/15 etc. to 1/1200. Shutter speeds of the newer progression are in red on a light, i.e. the finished aluminum alloy of the dial, back ground.

Shutter speeds of the old progression, 1/5, 1/10, 1/25, 1/50 and 1/100 (but not 1/200) are light on a black back ground. Remaining speeds are black on aluminum back ground.

Interesting, isn't it Well I think it is.

David

So Weston added the new progression to the old when Gossen already had disbanded the old for the new, after a period of presenting both...

My Agfa Isolette I from probably 1953/4 has the old shutter speeds of 1/25th 1/50th and 1/200th

pentaxuser

Chan Tran said:

With the advance of shutter less camera which the shutter is purely electronic it can be very precise so the series should be changed to 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192 so they are exactly 1 stop apart.

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I guess they could technically do this, and it makes sense.
For ease of thought and communication (usability), i would keep the simpler notation on the surface - i.e. say 1/500 not the actual value of 1/512.