Archived posting to the Leica Users Group, 2019/08/13

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Subject: [Leica] Putting X-Synch on a 100 Year Old Camera
From: amr3 at uwmalumni.com (Alan Magayne-Roshak)
Date: Tue, 13 Aug 2019 17:20:47 -0500

Peter Dzwig asked me about putting X-Synch on my ca. 1917 4x5 RB (Revolving
Back) Graflex.
Here's the story.

The camera that I bought to go with my 9" f/4 Wollensak Verito Diffused
Focus lens that I got for $12.00 in 1985:
<
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/Gear/MR_Graflex_1_Orig.jpg.html
>

Side view showing the wiring path:
<
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/Gear/MR_Graflex_2_X-Synch.jpg.html
>
The Graflex has a focal plane shutter with multiple slits and spring
tensions.  When the shutter is set to "O" (for open) the film
plane is uncovered but the mirror blocks light from exposing the film. With
a high tension, when the shutter button is pressed, the
mirror flips out of the way, trips the shutter, the entire film area is
exposed for a fraction of a second, and then the shutter curtain comes down
and covers the focal plane.  I made some contacts out of Aurora HO-scale
slot car pick-ups and mounted them so that the one on the mirror reset
lever would strike the stationary one at the moment after the mirror was
up, but before the shutter
curtain comes down to cover the film.  I can adjust the timing by loosening
the set screw on the arm, and varying the angle
of the moving contact.  The wire ends in a standard PC fitting.  The lead
going down and inside is for the microswitch in
picture five.

Closer view with mirror down and shutter cocked:
<
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/Gear/MR_Graflex_3_X-Synch.jpg.html
>

Closer view with mirror up and shutter tripped:
<
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/Gear/MR_Graflex_4_X-Synch.jpg.html
>

If I didn't do anything more, the flash would fire again as I reset the
mirror lever for viewing, so in the mirror box I
added a microswitch that only completes the circuit when the mirror/shutter
release lever pushes against it.  When the shutter
button is released, the switch opens the circuit and the external mirror
reset lever can swing past the stationary contact without
setting off the flash.

Microswitch and internal mirror release lever:
<
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/Gear/MR_Graflex_5_X-Synch.jpg.html
>

I usually like to use this camera with a Graflex 2-1/4 x 3-1/4 roll film
back, so when I'm employing electronic flash, I have
to do this for every shot (except the dark slide only needs to be pulled at
the start and pushed in at the end of the roll).

1. Have shutter set to "O" and mirror down.
2. Focus and compose (remembering to orient the roll film back to match
rectangles for vertical and horizontal shots drawn on the ground glass).
3. Trip shutter.
4. Wind film to next frame (there's no double-exposure prevention).
5. Reset mirror to viewing position.
6. Rewind shutter to "O" position.
7.  Steps 2, 3, 4, 5, & 6 for each of the remaining seven frames.

Simple.
-
Alan

Alan Magayne-Roshak, Senior Photographer
University of Wisconsin-Milwaukee Photo Services
(Retired)
UPAA Photographer of the Year 1978
UPAA Master of the Profession 2014
amr3 at uwm.edu
http://gallery.leica-users.org/v/Alan+Magayne-Roshak/

"All the technique in the world doesn't compensate
 for an inability to notice. " - Elliott Erwitt


Replies: Reply from cartersxrd at gmail.com (CartersXRd) ([Leica] Putting X-Synch on a 100 Year Old Camera)
Reply from don.dory at gmail.com (Don Dory) ([Leica] Putting X-Synch on a 100 Year Old Camera)
Reply from jhnichols at lighttube.net (Jim Nichols) ([Leica] Putting X-Synch on a 100 Year Old Camera)
Reply from pdzwig at summaventures.com (Peter Dzwig) ([Leica] Putting X-Synch on a 100 Year Old Camera)
Reply from richard at imagecraft.com (Richard Man) ([Leica] Putting X-Synch on a 100 Year Old Camera)