[LargeFormat] Dealing with Bellows Sag

[Clive Warren]

Most larger cameras have hooks at the top of the bellows to allow some 
solution to be put in place to deal with bellows sag when using lenses that 
require a middle extension of the bellows.

Now, I have never seen the gizmos that are supposed to be used to support 
the bellows when sag is an issue. I am assuming that the manufacturers 
originally supplied rods to be used in conjunction with the hooks. The rods 
would presumably be balanced across the rear and front standards.

Does anyone have the original solution (rods?) or have any advice on the 
best ways of dealing with the sag that would otherwise cause vignetting?

Cheers,
            Clive