Hi:

A friend have just asked me a question which I can't answer, so I am turning to you for help. He has just purchased a used M3 body, and he can't figure out the proper setting of the ASA number on the camera body. The ASA number of the older M bodies has different calibrations than the M6 ISO number. For example, the most commonly used film of my friend is ISO 100 for slide film and ISO 400 for black and white negative. And the ASA number of the M3 jumps from ASA320 to ASA650 with two clicks in between. My question is how do you set or calculate the ASA numbers of the old M bodies so that it would match with the ISO numbers of the modern film?

Sincerely,

Edward

-- Edward Yu (fallot@ms2.hinet.net), December 12, 2001

Answers

Edward, Realize that the only function of the ASA setting on the back of the early M's--M3, 2, and 4--is a reminder of the type of film one has in the camera. The center piece, if I recall, has three pointers--one with a bulb for indoor color film, one with the sun for outdoor color film, and one in black and white. One does have to interpolate the ASA, eg the two steps between 320 and 650 probably represent 400 and 500. Remember this functions only as a reminder, not as a meter as is the case with the M6.

-- Henry Chu (heninden@yahoo.com), December 12, 2001.

You are perfectly right, Henry. The disk on the back of the M3 only functions as a filmreminder. It shows symbols of b/w-film, colourfilm and tungstenfilm with different filmspeeds.

I do not have an M3 but with my M2 with and a LEICAMETER I do not use this gadged (because I need a reminder sometimes to remind me if I had set the right filmtype). Instead I stick a piece of the filmpack with ASA/ISO Nr. between meter and camera, thus preventing rubmarks on the top of it at the same time.

The only metered r/f-LEICAS were the M5, the CL and of course the long range of M6 cameras.

As far as your question regarding ISO and ASA goes, those numbers should mean the same. In the old days DIN-numbers were translated into ASA-figures which resulted in queer numbers sometimes.

Best wishes

-- K. G. Wolf (k.g.wolf@web.de), December 12, 2001.

25 32 40 50 64 80 100 125 160 200 250 320 400 500 640 800 1000 is the series of film speeds.

-- Michael Darnton (mdarnton@hotmail.com), December 12, 2001.

My 1954 Leica M3 has speeds going up only as far as 200ASA (now ISO for International, not American) Standards Organisation. That was fast back then! What was medium? About 25 or 32 for colour film of any kind, I think, and not very much faster for B+W, though I wasn't around. Of course, DIN (the still current German standard) and other obscure ones such as Scheiner were also used. Later M cameras steadily added a few more notches to their film speed dials. As a reminder of what film you are using, why not tear of the end of the cardboard film container and fix it somehow inside your case, assuming you are using one?

-- David Killick (Dalex@inet.net.nz), December 13, 2001.