[QUOTE=titrisol]
The A-series is supposed to be a load better though.
QUOTE]
Just to be clear - SMC means Super Multi Coated. SMC lenses were available in screw mount and in the first bayonet mount (K mount, Pentax M lenses). The only difference in bayonet lenses between SMC and SMC-A is that the mount (KA mount) has extra contacts and works in program mode - the glass is the same! The big quality difference is with autofocus lenses - some are great, some are hopelessly sloppy!