I know that I've seen the possible answer here somewhere, but my patience is waning with the search so I'll ask you all. I have just accquired an M4-2 and everything seems normal (by my limited experience) except that the shutter dial has a click stop between 1/8 and 1/15. This I don't seem to remember with an M2 I once had.

Also to clarify the slow speed sounds between 1 sec and 1/8 (much has been posted on this I realize), after the shutter fires and has closed should the escapement make a buzzing sound ala a self timer? BTW, I have run a test roll thru and am awaiting the results. Thanks for any answers and insights.

-- Dave Doyle (soilsouth@home.com), November 16, 2001

Answers

Don't know about the click stop between 1/8 and 1/15, I don't recall it on my M4-P which should be almost identical to the M4-2 in this respect. I'll check tonight, though.

buzzing sound:
Perhaps a little understanding of how a focal plane shutter works is in order.

X sync speed (1/50 second) is the shortest shutter speed at which the film gate will be 100% open during the course of exposure (with a minimum of 1/750-1/500 sec time duration wide open).

At all speeds faster than X sync speed, exposure is determined by the size of the slit made between shutter curtain 1 and 2 ... it's the sum of the time the film is exposed from the point when curtain one exposes it to when curtain two covers it at each point in the frame.

At all speeds slow than X sync speed, the exposure time is regulated by delaying the time between when the first curtain reaches the other end of the film gate and when the second curtain is released to close. It's the same integral as above, but there's a timing mechanism involved.

On a mechanical shutter like the Leica M, this timing mechanism is a small escapement geartrain much like a quality mechanical watch. The little buzz you're hearing is the sound of that escapement mechanism operating ... between 1/50 and 1/ 15 second, it just doesn't run for long enough to be terribly audible. On an electronically timed shutter, this mechanism is silent (usually a solid state clock of one type or another driving a magnetic release).

Hope that helps.



-- Godfrey (ramarren@bayarea.net), November 16, 2001.

The shutter sounds are normal. The click-stop between 1/8 and 1/15 is not. However if there are no problems and the camera otherwise doesn't need a CLA, it isn't something I'd lose sleep over.

-- Jay (infinitydt@aol.com), November 16, 2001.

Dave, I have several M's and I often hear a similar sound. It's a little duller than the speed indents and occurs in the location you've noted. Realize that the slow speed mechanism is different than the faster speed. (Don't ask me to explain.) As one turns the speed dial down to the slower speeds, the slow speed mechanism engages. You tend not to hear it, or feel it, as your turning the dial from slow to fast though.

-- Henry Chu (heninden@yahoo.com), November 16, 2001.

Thanks for the response, one other thing I noticed the black wax plug appears to be stamped with a D not the usual L. DAG perhaps?

-- Dave Doyle (soilsouth@home.com), November 16, 2001.

The M bodies (including mine) which I've seen that were done by DAG had a "92" stamped in the wax seal. Sherry Krauter's had a "K" which appeared to be hand-done with an instrument rather than stamped. I haven't ever seen a "D"...meybe someone else knows.

-- Jay (infinitydt@aol.com), November 16, 2001.

The last time this question came up (or maybe it was on one of the other Leica lists), the conclusion was that the click was normal. Mine has it, too. I assume you're not referring to another "real" clickstop--just a gentle resistance between those two speeds. The other thing you should have is a nice rebounding bouncing gear sound "zip-zip-zip" at 1/15. If I had to guess, the little click is the gear train switching between the zip,zip,zip mode and the ZZZZZZZZZZrrrrrrr one.:-)

-- Michael Darnton (mdarnton@hotmail.com), November 16, 2001.

Well as it stands, the X sync is not working and the M sync is hooked to the hot shoe, but the speeds seem to be spot on. Interesting. Thanks for all the response.

-- Dave Doyle (soilsouth@home.com), November 16, 2001.

Time to send it in, I guess. . . .

-- Michael Darnton (mdarnton@hotmail.com), November 16, 2001.