35mm Canon series has become a pivotal force in the field by a growing number of professional, amateur recognition. Canon EOS series for the camera AFai new era of development of the EF series of lenses, from 14mm up to 1200mm total of nearly 60, both senior professional "L" head, there are mid-range amateur first, more low-end consumer-level head. Canon camera products in these large-scale use of new technology, different grades of products using different technologies, in order to facilitate the early entry-friend correctly identified, the right to choose the appropriate lens, here specifically for the grade classification of EF lenses and motor Technology to make a brief introduction.