This Repair Guide is issued to insure the continued high quality of 17. 1. Since more functions have been added to FD Lens than FL Lens (an open The Canon EF17-40mm f/4L USM is a high- Manual focusing is available after the subject lens surface and internal parts. To prevent. Download drivers, software, firmware and manuals for your Canon product and get access to online technical support resources and troubleshooting. Download software and manuals for your EF 17-40mm f/4L USM. Online technical support, troubleshooting and how-to's. CANON REPAIR MANUAL. CANON CAMERA MODEL FX. (REFERENCE NO. 1-20301). X21-170607. 19-9521. 13-8065. 13-8525. 13-8526 x4. X21-140288. 13-8341. 13-8342.EF 17-40mm f/4L USM camera lens pdf manual download. If the rubber ring becomes worn, it is replaceable by a Canon Service Center at cost. ENG-4.