My usual retailer (who is a fine Pentax collector BTW) told he usually tends not to sell Sigma lenses because of frequent incompatibilities (dunno if it affects Pentax compatible lenses). Sigma optics are usually compatible with bodies available at the time the lens is out. But older or newer bodies often have problems.
The reason (according to him) is that Sigma is NOT working under licence from the original manufacturers. And they are the only ones. Even Vivitar does. Tamron, Tokina etc. do too. No licence means reverse engineering IMO so no wonder there are problems. I have no way to check this information and thought it could be of any help to the community. ---------------------- Thibouille ---------------------- *ist-D,Z1,SFXn,SuperA,KX,MX, P30t and KR-10x ...
