New answers tagged error
You want to contact Sigma and find out if they'll still rechip the lens. Given the age of the lens and the fact that you're not the original owner, they may not be able to rechip it, or might charge for it, but it's worth a shot--the worst they can do is say no. Third party lens makers typically reverse engineer the electronic communication between the ...
Have you got the latest firmware for the camera? If not, try updating it. http://www.canon.dk/support/consumer_products/products/cameras/digital_slr/eos_40d.aspx?type=firmware
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