[Michal1]

Hello, I'm building a vacuum back for P67. I need to dismount the pressure plate from the camera's back door. How can I do that? The service manual says it is attached by the "pressure plate retaining screws". However, they are tight. Is there any special trick to unscrew them? Thanks.

[Silent Street]

The big question: why do you need a vaccum back for the 67? It will not provide any improvement in image quality from the engineering that is standard on the 67. Practical considerations would remove much of the straightforward ease of use of the camera, such as the need to remove backing paper from film and the requirement for loading and unloading in a dark environment. A great many screws of any size on the 6x7 / 67 bodies are quite tiny and difficult to remove, usually done so with pneumatic drives with adjustable torque (very slow and firm). If you can imagine the torque wrenches that tyre repairers use to remove and install wheels, that is what I have observed with techies servicing an old 6x7 body — a very small and precise instrument (air-powered). I don't know if such things are commonly available or a specialty service item. Otherwise you'd be restricted to using jeweller's screwdrivers and an extreme amount of caution.

[Michal1]

Thanks for your reply Silent Street. I use the camera for astrophotography, i.e. I must use exposure times around 1 hour. With an unmodified camera, film loses tension in a few minutes after rewinding. Film curl degrades my photos frequently. I'm aware of the drawbacks of a vacuum back, but its benefist are greater for me.


Please can somebody confirm me that the pressure plate is held only by ordinary screws?