The Secrets of 

The Build In Shutter Release 

The shutter on the front is tripped when pressure on the body release is transmitted by a Bowden cable, actuating the shutter release arm next to the shutter on the standard.


At the first glance the shutter release is a simple button, however, the shutter release appears to be quite an ingenious, well designed and reliable assembly which finds it place on the right side of  the camera body . The camera house is made of special Honduras mahogany wood and dovetailed to resist heavy climate changes and rough treatment. One of my Large Format camera  friends Barend Jan van Spaendonck could not resist the challenge to take a look behind the leatherette to find out how the build in shutter release mechanism  works. First of all he removed the plate of the release slide as well as the trim on the front, then he started to peel off the leatherette, beginning at the bottom side of the body, using a cotton tip with some drops of contact cement solvent or acetone to remove the glue.                                            



After successfully removing the leatherette, he unscrewed the plate assembly body release mechanism.  It exists out of a plate d  - the trigger release a -  spring c and finally the cam b to operate the Bowden cable inside the body.


Squeezing  the body release lever a moves the cam which is connected to the Bowden cable inside the camera body, which controls the release assembly on the front standard (photo on the right). The cable pulls the rod down and the release arm trips the shutter. To make it a bit more complicated, the Speed Graphic is equipped with a focal plane shutter as well. The focal plane shutter is also controlled by the build in shutter release, but previously the shutter must be selected by the shutter selector slide on the black crackle hardware on the right side of the camera. Selector reads: Trip, Back and Front. Apart from that, the release button is connected to an electric circuit to disable the function of firing when not using the build in release button. That means that winding the focal plane shutter does not fire the flash, nor tripping the shutter with the slide selector will activate the flash. 


The Speed Graphic with removed Kalart rangefinder housing, focal plane rollers and focal plane shutter plate assembly. 

Photos copyright Barend Jan van Spaendonck and Jo Lommen

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