1/2000 sec Leica M shutter speed?

Yes, I know there's no 1/2000 sec dial on a Leica M camera body. However, I was recently messing around with my

M3 shutter speeds and discovered I could get consistently 1/2000 sec and higher, on the speed dial set to 1/1000

sec by adjusting the shutter springs. So why didn't Leica never put a 1/2000 on an M body? Your hypothesis

please...

Probably no demand and too much tension on the springs.

The top shutter speed is set by the curtain speed, and the need to keep the slot wide enough to not cause diffraction results. The slot also has to be wider than the surface roughness of the edges of the curtains.

 

It would be very hard to get any sort of consistent operation of an M cloth shutter at twice the travel speed. Inconsistency, curtain bounce, quick wear of the brakes, and quick wear of the bearings. You would need a CLA every year...

I have owned three M series cameras and none of them approached 1/1000 sec when set for a thousandth. A dealer once got curious when I told him about this. He took a brand new Leica M 6 out and tested the 1000 setting. It read 1/650. What I wonder is: Has anyone had his M-series tested and found one that was 1/1000 or higher?

 

With my current camera (M4-P), the lower settings are very close to their true settings, but the 1/1000 reads about 1/555.

Maybe it can't maintain that much tension and accuracy.

FWIW both my M2 and M3 showed 1/1000 quite a bit faster just prior to CLA (due to sticky low speeds), judging by the thin neg I got when

running a series of equal EV exposures. All the other speeds above 1/30 were consistent zone V density but 1/1000 was about zone IV,

ie. approaching 1/2000. The M2 still had the L seal so had not been tweaked in 40 years.

The speed of the curtain is constant in a Leica. The shutter speed is controlled by the delay time before the rear curtain is released. The faster the shutter speed, the quicker the rear curtain is released. Above 1/50 second, the rear curtain is released before the front curtain clears the frame, so the shutter opening becomes a slit. At 1/1000 second, this slit is very narrow (about 2 mm), so small errors in timing make a big difference in exposure.

 

The shutter of a Nikon SLR (F5 and newer) moves at least 5 times as fast and is more precise (and noisy), so the maximum shutter speed is as fast as 1/16000 of a second.

The M7 has the most accurate 1/1000s shutter speed in the film M-line because of it's electromagnetically controlled

shutter. The M7's springs are probably different from the MP cameras shutter. 1/2000 is available from Voigtlander and

Zeiss M mounts, and 1/4000 from the Hexar RF cameras and the M8.

Didn't the Olympus OM-4 have a cloth horizontally running shutter with a top speed of 1/2000?

Its usually a bad practice to achieve an ultra high focal plane shutter speed thru a large tension; it often doesnt hold and drops with time. It makes the springs "creep" more; ie thru a higher stressed spring. Its a basically a tradeoff of either using an ultra high tension; or a narrower than normal width to hit 1/2000 second on a horizontal FP shutter on a 35mm camera. With two curtains the timeing ; transit speed; slit width grows worse as one makes the slit on a given design narrower. One could make the shutter speed 1/4000 by making the slit 1/4 the gap as the 1/1000 setting; folks would get an exposure that varied across the image; folks would bitch.