Adjusting Compound Shutters

[Kevin Crisp]

There are two little screws on either side of the shutter at the top, on the front. Apparently these are speed adjustments? Does anyone know specifically which is supposed to do what? (And if you do, turning clockwise does what?) Thanks. I found the Ed Romney book rather uninformative on this subject.

[Paul Fitzgerald]

Hi there,

There is no speed adjustment on a Compound air shutter, it is controlled by the piston on top. The only way to adjust the speed is to use oil on that piston. You can use differnt vicosity oil to get slower and slower speeds till it stops moving. The only 2 screws at the top are:

to remove the face plate (outside)

or

to remove the top cylinder (inside)

Turining them clockwise tightens them.

Which type of compound shutter is it, B&L or F. Deckel(Germany)?

[Kevin Crisp]

F. Deckel. Thanks.

[Jim Galli]

Kevin, the bigger Compounds do have a screw that goes through the exterior front cover for speed tweaking. It is a cam that increases / decreases spring tension on a main spring that drives a lever that in turn drives the air piston. My experience has been just the opposite of Pauls. I remove the air piston and clean it and the cylinder to near clean room conditions and never oil them. There were both German (most) and American (Bausch & Lomb license) made Compounds. Quality is certainly equal between the 2 but threads are different making parts between similar sized American and German Compounds not interchangeable. The Chrome "caps" at either end of the air piston originally had paper gaskets to make an air seal.