THE CAMERA BETWEEN THE LENS SHUTTER
Intensity ----- Duration ----- Alignment of the lens
Care and upkeep of shutters
The shutter assembly has three very important functions. the first and most obvious is of course control of exposure time to the film. The shutter blades and timing control machinery do this job and can continue to do it well in shutters made over a century ago. In most shutters made in the last century the shutter assembly also includes an aperture blade set to control both light intensity and optical properties of the lens.
Third the shutter provides extremely precise positioning of the front and rear cells of the lens. this function is probably the most vulnerable to damage due to the shutters fragile body easily being crushed by being pressed too hard or being dropped as little as 2 feet onto a hard surface such as a table top or floor.
A shutter that has been dropped may in severe cases of crushing even show the damage as obvious deformation of the shutter body and may even have shutter blades drop out of their pivots. In most cases of damage however a shutter will continue to work fine mechanically however the front and rear components of the lens mounted in it may no longer be in correct alignment. With tolerances in lens construction as small as 1/10,000 of and inch [and sometimes even less] a crushed shutter lens mounting surface may be off from damage more than 5/1000 and still work mechanically fine moving and timing its shutter blades but unfortunately image quality is probably seriously degraded.
There is a reason that the most precise lenses made for tasks such as photomechanical work and other critical applications were never mounted in shutters but instead screwed into solid monolithic barrels which were both more precise than shutter mounting to begin with and at the same time nearly invulnerable to the sort of accident that can ruin the alignment of a lens components mated to a shutter.
Cleaning and re lubrication of a shutter is most commonly needed after original lubrication has dried out and been gradually contaminated with dust and dirt. Frequently shutter blades become contaminated with lubricant that has the effect of preventing partial or total movement of the blades. In a Kodak Syncro 800 shutter which has two sets of shutter blades the rear pair of blades which cover the aperture during cocking of the shutter can be ripped apart if they become contaminated with oil on their surfaces. [ This shutter is used in the Kodak Chevron camera and other cameras]
Aperture blades similarly if contaminated with even a tiny amount of grease or oil can be easily destroyed simply by trying to move them while stuck together.
Despite information you may hear to the contrary all shutters require lubricant at all bearing and contact points to work correctly and not suffer damage. Even shutters that are to be used in extreme cold environments need their own special lubrication.
As many as 5 different types of lubricant can be needed to meet the requirements of some parts that move at high speed with miniscule forces and others that on heavily pressure loaded surfaces need lubrication equal to that of heavy machinery.
Fortunately modern lubricants can allow even ancient shutters to work sometimes even better now with our superior lubricants than when they were first used such as this 19th century pneumatic Goerz shutter to the right which belongs to a family of shutter design that combined both shutter blade and aperture blade function into only one set of blades.
Single acting shutters both cock and release by moving only one lever. Double acting shutters require first cocking usually with one lever then release by another lever. A few shutters switch between single and double action for T/B [ single] and timed instantaneous speeds [ double] like early Compur and Compound shutters.
In addition to the primary three functions of : Intensity ----- Duration ----- and Alignment of the lens, most more modern shutters also have electrical contacts for flash.
Labor cost for most "view camera type" shutters is usually $ 170 ... to strip original lubricant, dirt, and what not out then lubricate with modern lubricants, test and provide an actual tested speed card.
*WARNING !!! The Chevron uses the Kodak Syncro 800 shutter.
The Syncro 800 has two sets of shutter blades.
The rear pair cap the opening during cocking of the front primary blades.
The capping shutter blades are actuated to open the aperture for making
a picture directly by the trip lever via a pin passing through each blades pivot slot.
If any lubricant such as oil or grease contaminates the blade pair
they can effectively stick together and the force of moving the trip lever
will frequently tear the blade pivot slot on one or both blades.
These two blades can be examined through the rear of the lens
and if they show ANY sign of not moving freely or contamination strictly
avoid attempting to use the shutter until it has been cleaned.
LINK TO: THROUGH A VINTAGE LENS BY T. RAND COLLINS MD
LINK TO: ANTIQUE CAMERA PHOTO GALLERY
Two stereo lenses in shutter for use on 5x7 size plates and film
Rolleidoscop C. 1924
Wollensak Optimo double ended blade shutters [ large and small ]
E& H .T ANTHONY & Co.1898 Catalogue What cost $17 in 1898 would cost $432.60 in 2009
Add $141.44 for the Aluminum fancy version http://www.westegg.com/inflation/
And that is WITHOUT A LENS.
Triplex with 3 component lens set set.