I bought a Canon 750 (35mm film) today with 3 Sigma AF lenses, a 75-300mm, a mini-wide 11 24mm and a 50mm macro. Having used a manual mini-wide 24mm and a manual 50mm macro on my Pentax I was hoping that I might use these on my 40D or 450D. Unfortunately they do not work with them. A quick trawl on the internet shows this is a problem due to Canon making a small change to the chip that meant Sigma, not being a licensed EF mount had to re-chip their existing lenses. The re-chipping appears to be no longer available. However I have read that the Canon D30 can use them. Does anyone know if that is true and if there are other very early Canon DSLRs that are able to use them?