What are the differences between the various B+W filter mounts?
F-Pro: Compared to the earlier standard mount introduced in 2001, the F-Pro mount has become thinner. Now it can be used with wide angle lenses, including most 24mm focal lengths on a full frame body, without vignetting. Another advantage of the F-Pro mount is it’s modified retaining ring, which is no longer threaded in from the front, but holds the filter glass in place from the back. When removing a filter or lens hood that has been screwed on too tight to the filter, the retaining ring is not at risk of loosening. Diopters are mounted in the older mount due to glass thickness. XS-Pro Digital: This mount is especially suited for DSLRs with wide angle and zoom lenses. It has a front thread for additional accessories such as lens caps or hoods. All XS-Pro Digital mounts are made of brass and are matte black to prevent reflections. Only UV and Clear filters are offered in this mount at this time. Slim-Line: This mount is for wide angle lenses. They do not have a front accessory thread t
