佳能答复原文(估计很多朋友有同样问题)

Thank you for your E-mail inquiry regarding your Canon EF lens. Using the lens on the EOS 30D digital camera there would be a 1.6x multiplication factor on the lens. Therfore the EF 28-80 mm lens would act as a EF 45 - 128 mm lens when attached to the EOS 30D digital camera.
All Canon EF lenses compatible with film based EOS SLR cameras are fully compatible with our EOS Digital SLR cameras. This is due to Canon's innovation in placing advanced electronic circuitry within the EF lenses. Due to the difference in size between a 35mm frame and the image sensor of the digital camera, the focal length of the lens may increase. Should you wish to obtain further details on Canon digital SLR cameras, please feel free to visit our website at:
http://web.canon.jp/Imaging/enjoydslr/index.html