Another problem with the B&W filters.
Also noted that if you screw the filters on firmly to the lens that this inhibits the aperture ring from turning.
The screw length on the B&W filter is a bit on the long side, so you can't screw it in all the way without making it difficult to turn the aperture ring.
Solution is to put a spacer (or blue tack) so you don't need to turn the filter all the way in.
Sorry for the poorly worded message, but for those of you that have this lens, you'll know what I'm talking about.
Best
Rob