- Posts: 249
- Joined: Tue Sep 17, 2013 8:08 pm
You only need the shims to set the back focus on a PL zoom, if it is not staying in focus during the zoom.
If your lenses are properly collimated and set for the correct FFD, you should not need the shim kit, unless you need to adjust the FFD to get the witness marks correct.
Given you sre using Cooke lenses, they should work fine without adding shims. That said, one if the advantages of thenPL Mount, is you can change the FFD with shims if necessary.
Cheers