Question about aperture setting on old compur shutters

[Douglas Henderson]

This is in regards to the old Compur shutters dating back to the 1930's or so, the ones with the iris functions and shutter speeds determined by separate little wheels. The aperture scale lever is not marked with a clear arrow, but with a stepped knotch shape. It is unclear exactly where to set it for a proper F-stop. Does the F-stop number fall within the lever notch? Or cover the F-stop number? Or should you line up the straight side of the lever with the F-stop number and its dash mark?

I tried comparing the size of the aperture opening with other lenses of the same focal length--but this wasn't as useful an idea as I thought, as the apertures didn't seem to match exactly at F22. Should they match between different lenses of the same focal length?

[Louis Pacilla]

It should be when the straight edge shows the proper f stop on the right side( facing camera).

I think is what your looking for.