View Full Version : Prontor Pro 1s and Copal....thickness??

5-Dec-2008, 15:15
Hi, what if I want to change a lens from a Prontor pro 1S to a Copal 1 shutter. The thickness is indicated with 20mm in both cases. In fact, I have two identical lenses with slightly different spacing rings (ie the focal length is not exactly the same I presume).
Can I swap shutters without problems, or is there any danger that both lenses won't be corrected precisely anymore? In fact, is the spacing ring for correcting the lens itself (and therefore the distance between front and rear element, that's what I presume), or is it to compensate for shutter thickness differences (I couldn't believe that).

thank's for an info

Peter K
5-Dec-2008, 15:26
Hi Torsten,

the spacer has to go with the lens, because the front and rear mounting lenght of all modern shutters size #1 is 20mm +/- 0.025.


Peter K