]Some of these "petal" lens shades wouldn´t work, that´s true, but I ]´ve not seen any lens with that kind of rear baffling (possibly I´m ]not enough of a W/A man). Per Well I just checked all my lenses and it seems you are right - everything is circular. The one I was actually basing my thinking of was my old 14mm Sigma - but that got sold because the quality was crap (strangely true for all the Sigma lenses I bought early on :o) Since I don't have it anymore I can't be sure. Bob PS: some of the petal hoods go for over 30 UK pounds. Not an inconsiderable amount of money.