[Leica] Flash delay contacts / Stan

[Leikon35 <Leikon35@aol.com>]

<<     I would assume that the adjustable synch on my IIIf moves the
 contact point 'ahead' so that the circuit completes before the lead
 curtain ends its travel, providing the extra time needed for bulbs to
 come to peak.
     So then, do I have it fundamentally right? Or, alternatively, am I
 (fundamentally) all wet? :-) 
 Stan Yoder
=====================================================
 Stan - Yes you are correct;  In the days when flash-bulbs were the norm -
 the IIIf dial had synch from "0" to "20" miliseconds delay and the flash
 duration was approx. 1/50 sec.  This caused problems with focal-plane
 shutters that took longer (1/30) sec for the slit to complete itself - so FP
 or focal-plane flash bulbs (longer duration were developed).  Many bulb
 makers and various size bulbs required different delays and Leitz designed
 the synch dial for the IIIf with variable delays.  Later on, the "M"s just
used
 two separate sockets; one for flash (20ms) & one for strobe (X) so you are
 fundamentally correct.

 As a note of trivia - when I was in high school, I owned & used a 4x5 Speed
 Graphic that had a focal plane shutter with 4 different sized slits and about
 10 tension settings.  As an experiment, I once removed the tension cover &
 gave the spring many more turns til I thought that I was getting 1/2000 sec
 exposure with the long duration #3 flash bulbs.  I don't really know for sure
 what speed I actually achieved but I got some incredibly sharp sport photos.

 Marvin Moss