This Canon AE-1 Repair Manual is a photo copy written by Lawrence Lyells in 1977-78 for the one time National Camera. This is the manual that all the repair people use. It has about 72 pages of GREAT information. It covers all the operations and controls of the AE-1 camera. It covers how to test all the operations and the controls, the removing and replacing of all major componets, the troubleshooting of all the electronic systems, the R&R of the famous tungsten wire. The R&R of the mirror box, shutter timing, etc, I could go on and on but I am sure you get the idea . This is a great manual.