Yes, a 30mm hole. Although Copal 0, 1 and 3 are standard sized shutters the hole required can vary slightly depending on the particular flange or retainer used. Most retainers have a lip that is meant to sit in the hole in the lensboard, so the hole should be cut to fit the lip, not the thread on the shutter. That doesn't always happen so you get a variance in sizes and I guess KEH learned long ago that it is better to list the exact size of the hole rather than Copal 0 or 1 etc.
The hole for a Copal 0 is nominally 34mm and Copal 1 42mm so a 30mm hole is undersize for most modern shutters. It is possibly an Alphax 0.
Last edited by paul ewins; 11-11-2012 at 11:33 PM. Click to view previous post history.
Reason: added hole sizes