I recently sold my Tamron 70-200mm f2.8 to assist my daugeter in her nursing career. Yesterday I found a Sigma 70-200mm f2.8 HSM II Macro with a Sigma 1.4x tc and Hoya circular polarizing filter at a great price. The lens is spot on with superfast focus. I attached the 1.4x tc and immediately all the displays start flashing and no auto focus. cleaning contacts and all the usual checks/fixes result in the same problem. I can switch to manual focus, but there is no focus confirmation and still the flashing lcd display. When i tested the sigma with the k7 and the f*300, everything works flawlessly.
Anyone else have this problem?
Last edited by ivoire; 12-30-2009 at 09:46 PM.