frankly, i really dun understand why Sigma buttock itch and put the EX coating on their lens. Somemore they still got the cheek to advertise it big big "EX LENS - signifies the professional quality of this lens." Wat the heck man, peel until like dunno wat = signifies how lousy sigma is.
The R&D team in Sigma should just cut their cost and remove their EX coating, and maybe then i will buy my first sigma lens. [yes yes... some of their current lens are non-EX, but the good optical quality lens by them are all EX]