I've been reading a review on the Canon 14mm 2.8L II, and one of the features (shared by quite a few ultra wides apparently) is that the bulbous front element makes fitting a filter on the front impractical, and they use drop-in gelatin filters at the rear.
I don't expect to be buying such a lens, but I am curious - how do folks with these lens' protect the front element (and its outward coatings) from dust, debris, and micro-scratches?
regards,
Nigel