M3 shutter speeds not standard?

[michael.panoff]

I recently acquired an early production M3, dual-stroke. For some strange reason the shutter speeds are labeled:

B 1 5 10 25 40 100 250 500 1000

What's up with that? Am I to assume that those numbers are accurate to the actual shutter speed. Therefore if I wanted a shutter speed of 1/60, I would dial somewhere between 50 and 100 (closer to 50)?

Thanks!
Michael

 

[ZorkiKat]

Not really strange. That M3 was made when the old "International" speeds (whose values are the series you quoted) were still in effect. A few years later, the "new" shutter speed values - the one which we use today- would become standard and such was used with the succeeding M3's.

I would not be concerned about what the "old" values actually do the exposure- 1/25 is 1/25, but not much different from 1/30. If you want a 1/60 sec exposure, the 1/50 setting will give your film practically the same dose of light .

 

[michael.panoff]

excellent, thank you very much. Any idea if the M3 supports in-between shutter speeds? I assume it would be, given it mechanically controlled.

 

[ZorkiKat]

excellent, thank you very much. Any idea if the M3 supports in-between shutter speeds? I assume it would be, given it mechanically controlled.

There is one old reference I remember which said that the M3 was capable of being set to intermediate speed values between 1/50-1/1000. Can't remember which version - even the S/S M3 with "new" speeds had a 1/50 setting for flash- this was or what the exact context of this statement was.

But the more pertinent issue is, why should one even try to use intermediate values between the marked speeds? Using a position between two marked settings on mechanical dials would not give precise values -if the shutter mechanism would do this- to the same degree as, say having 1/45 sec between 1/30 and 1/60 in electronically set cameras.

Intermediate shutter speeds won't likely give tangible differences in the exposure. BW and colour negative films would lose perceptible changes in exposure once they're printed.

And if intermediate exposure values are really required, such as in shooting reversal stocks, the better, more predictable way to go is to leave the shutter in its marked value and tweak the lens aperture instead. Note that some of the really old lenses didn't even have click stops on their f/stop settings- allowing "stepless" adjustments.

Jay

 

[ERV]

Many handheld lightmeters have markings for international speeds as well, which will allow you to select the correct readings.
The CV II meter does not, however I just use 60 for 50 and so on without any problems.

 

[richard_l]

I have an M3 with the old speeds. I just set the speed closest to what my light meter recommends, and there has never been a problem. Exposure-wise there's not much difference between the new and old speed markings. For example, the difference between shutter speeds of 1/50 and 1/60 is only about 1/4 stop.

I think anyone is probably lucky if the shutter speeds of their camera and the f-stops marked on their lens are off by only about 1/4 stop.

Richard

 

[StuartR]

If you took a shutter speed tester to your M3, (or any mechanical M), you would be surprised at how inaccurate they are. The difference between 1/25th and 1/30th is smaller than the error in the shutter. If you test the M3, you could expect it to vary by 1/3rd of a stop in either direction, so something from about 1/20th to 1/40th. And it does not stay consistent either. It may be 1/30th one day, 1/35th the next, and 1/20th another. If you want spot on accurate exposures, electric shutters are the way to go...that's what the M7 is for. All that said, you will not notice a difference on negative film unless you specifically test for it, and you will probably not notice it on slide film either. The difference is just not that big...

 

[michael.panoff]

thanks for the helpful information.. much appreciated!

So I gather the M6 has a mechanically controlled shutter as well?

 

[Rico]

excellent, thank you very much. Any idea if the M3 supports in-between shutter speeds? I assume it would be, given it mechanically controlled.

From my M4 manual, p.14:

"Intermediate shutter speeds may be set between the click-stop settings, except between 1/8 and 1/15 sec."

Speeds of 1/8 sec or longer are timed by the slow-speed escapement versus the high-speed. Your older M3 should have a similar twin-escapement design. The intermediate speeds are perfectly usable in my experience.

 

[OldNick]

The thing that intrigued me was the "40" in the initial post. I must assume it was a typo, that the number should be "50". Is that correct?

Jim N.

 

[VinceC]

Even if the mechanical shutter speeds are dead accurate (which they aren't, as above) the difference between 1/50 and 1/60 is nearly meaningless. You've got to go a third of a stop before slide film even really notices it. If you're looking for a dead-accurate slide-film exposure, you can compensate with the f/stops. If you're using a match-needle light meter, you can see the f/stop difference with the shutter speeds and set the lens accordingly.

 

[michael.panoff]

The thing that intrigued me was the "40" in the initial post. I must assume it was a typo, that the number should be "50". Is that correct?

Jim N.

You are correct, typo.

 

[michael.panoff]

Even if the mechanical shutter speeds are dead accurate (which they aren't, as above) the difference between 1/50 and 1/60 is nearly meaningless. You've got to go a third of a stop before slide film even really notices it. If you're looking for a dead-accurate slide-film exposure, you can compensate with the f/stops. If you're using a match-needle light meter, you can see the f/stop difference with the shutter speeds and set the lens accordingly.

thanks for the info.. gots to keep that in mind, been stuck in a DSLR mindset..