Anybody know what the difference is between an EX mount and an EF mount for canon? Are they the same thing? I'm considering purchasing a used Sigma 24-70mm f2.8, and they're all EX. Also the cheaper used EX versions look different from the New EX versions. If anybody knows anything I should consider before a purchase, please let me know.
Best,
Aveek
Best,
Aveek