In article , Me says...

No -it's just wider - same as the 12-24 on FX. It also can't be
fitted
with a protective filter, and every review I've read of it comments on
decentering issues.

The Sigma comes with a big lens cap, so there is no need for a
protective filter.

Not sure what you mean with decentering issues.
--
Alfred Molon

Olympus E-series DSLRs and micro 4/3 forum at
http://tech.groups.yahoo.com/group/MyOlympus/
http://myolympus.org/ photo sharing site