I was recently excercising the shutter on my M6, running through 1/1000 down to 1/2, 1/4 etc. I was listening to the sounds, which I really hadn't paid attention to before. At 125, 250 and the like, you have just a very nice "click". but at the long settings, such as 1/8, the is a sound after the shutter opens and closes. You can hear the shutter open, go through the timing, and then when it closes, a sort of "zing" afterwards.

Does anyone know what this is and is this normal to the M6?

TKS, P Nelson

-- Paul Nelson (clrfarm@comswest.net.au), January 19, 2001

Answers

It's called a "slow speed escapement" and most if not all mechanical shutters have one. The purpose is to hold back the second curtain from closing until the correct moment. When your Leica *stops* making those sounds it's time for a CLA!

-- Jay (infinitydt@aol.com), January 19, 2001.

My books on the Leica rangefinders say that one of the things you should check when examining a secondhand camera is for proper shutter function, which they say is easiest at 1/15th of a second. I would assume this is the threshold for the shortest speed that you can differentiate the following actions:

1. release- first blind moves. 2. second blind- released prior to first blind completing its run the second shutter is released but held back by slow speed escapment. 3. gear train- momentum of second blind causes the gear train to spin. 4. second blind- braking effect of slow speed train allows the second shutter blind to complete its path overlapping the first. 5. gear train- Recycles for next exposure by return spring.

I very much oversimplified the preceding actions, but in essence, you should definitely hear several actions after 1/15th of a second down to the slower speeds. The Hove pocket book has the whole process if you are interested... insisting that a properly functioning shutter can be identified by having all of the actions clearly heard.

I would say your M6 is fine.

-- Al Smith (smith58@msn.com), January 19, 2001.

After you've done this for a few years,you can tell if a shutter is timing the slow speeds correctly by their sound. 1/30 sec is "click". 1/15 is "clicka." 1/8 is "cli-ick." and so on.

-- Bill Mitchell (bmitch@home.com), January 19, 2001.

Funny, I wouldn't describe it Bill's way. To me, 1/30 and 1/15 have what I would call an "aftersound" like a ball bearing bouncing on a marble table top. This must be stage 5 in Al's description. At 1/8, it sounds like "RRRrrr" (the aftersound) sort of like my cat growling.

Oh, well.

-- Bob Fleischman (RFXMAIL@prodigy.net), January 19, 2001.

I hear the same sound as the last poster-almost a self timer kind of sound after the fact on speeds below 1/25 (on my older M3.

-- Andrew Schank (aschank@flash.net), January 20, 2001.

I was only referring to the timing interval sounds, Guys. I hear the same buzz afterwards as you refer to. The timing interval sounds are even the same on focal plane and BTL shutters; I thought it was a neat trick.

-- Bill Mitchell (bmitch@home.com), January 20, 2001.

I hear the same sound as Bob describes after 1/15 and 1/30, almost a kind of little rattle which is not there on any other speeds. "A ball bearing bouncing on a marble table top" is an apt description, however I don't remember hearing this sound on the other M6 I once owned.

-- matt veld (mahv@xtra.co.nz), January 20, 2001.

B-zzzz-aaa

-- grant (g4lamos@yahoo.com), January 20, 2001.

Snap...crackle...poop. Let's get on with it. :~(

-- Ken Shipman (kennyshipman@aol.com), January 20, 2001.

Grant must've eaten beans.

-- Jeff Spirer (jeff@spirer.com), January 21, 2001.

Yes, gentlemen, it is the sound of the "slow governor" switching from 1/15.

-- Victor Randin (www.ved@enran.com.ua), January 22, 2001.