Home > Consumer Reviews > Sigma 150mm f/2.8 EX DG HSM APO HSM IF Macro Lens for Olympus and Panasonic SLR Cameras

I purchased this lens about a week ago. I have not had the opportunity to shoot many pictures with it but from the first time I tried it the Auto Focus failed to work with the shutter button. It does focus (fairly accurately) with the AF button on my Canon 40D. I contacted Sigma and after 4 days they had not given me an answer. I wrote again and the reply I got was that maybe because the 40D was a new Canon model the engineers had not taken some adjustments into account. They also said that it would take them about a week to get a reply from the engineers.
With Canon I usually get a reply to my email within one day and the explanations to my questions are accurate and to the point.
This is not a cheap lens but compared to a Canon L lens its very much less. I guess the poor service and the engineering flaw is the difference in price between a Sigma and a Canon L lens.