[Leica] Identification of odd shutter speed knob on IIIc

["Doug Richardson" <doug@meditor.demon.co.uk>]

From: rurmonas@senet.com.au (Richard Urmonas) wrote:

>Rather than a round knob with a knurled edge, my
IIIc is fitted with a "tri-lobal" knob.  That is it is round but has
three projections on it.  The overall shape is not unlike that of a
Wankel
engine rotor.


Hello Richard,

I think that your camera has been fitted with the CAVOO speed-setting
dial - part of a flash synchronisation scheme which Leitz devised for
pre-IIIf screw Leicas. The cam was designed to work with a device
(VACU I seem to recall) which fitted over the normal shutter release
button. As the shutter dial turned, the cam initiated the operation of
a flashgun plugged into the VACU. I've seen references in older books
to a synchronising dial fitting over the existing speed-setting dial,
but have never owned one so can't be sure. I suspect that your dial
was fitted in place of the original.

Regards,

Doug Richardson