You could also take the B&W's new "XS PRO DIGITAL" mount. It is even slimmer than the "slim" version (especially designed for lenses wider than 24-28mm) plus it has a front thread. The normal canon lens cap will fit.


Just don't confuse them with their "DIGITAL PRO" filters, they are for pocket cameras and have a chromium finish. (probably even don't exist for 82mm). You will want the "XS" label.


The XS PRO DIGITAL originally came in one flavour only, "007 clear glass" without UV filter, but this is not needed on digital sensors, as far as I know. Perhaps they have the "010 UV" also in this mount by now.