Camera lens I bought on ebay a Sigma 90mm f2.8 AF macro Minolta mount lens. It works perfectly okay on my Minolta Maxxum/Dynax 7 film camera (so there doesnt seem to be a malfunction in the lens) but will not function in automatic mode on my Minolta Maxxum/Dynax 5D digital SLR. I cannot understand why not. I have another AF Sigma lens (70-210) which works in automatic mode on my 5D. I have contacted Sigma and the ebay seller but neither can help. Please can you advise me. Thanks, Martin

Yes, JoelB is correct. As the only Authorized Facility for Sigma lens in the Southeast. We do go through rechipping service wholelot. Once you give them correct model, simply Sigma will give you straight answer whether upgrade chip is available or NOT. Good luck. James. Here is our facility web site www.camerarepairjapan.com

It sounds like a CPU chip incompatability issue. Sigma has that problem sometimes but are usually very good about rechipping at no cost (at least for Nikon-mount lenses). What did they say when you asked them?