When we buy new device such as Canon EF28-70mm f/2.8L USM we often through away most of the documentation but the warranty.
Very often issues with Canon EF28-70mm f/2.8L USM begin only after the warranty period ends and you may want to find how to repair it or just do some service work.
Even oftener it is hard to remember what does each function in Camera Lens Canon EF28-70mm f/2.8L USM is responsible for and what options to choose for expected result.
Fortunately you can find all manuals for Camera Lens on our side using links below.