Manual focus is the direct control of a camera/lens's focus by the photographer. This is generally accomplished by turning a focus ring which is mechanically coupled to the lens's focus, but some cameras without focus rings allow manual control over the autofocus motor.
I've been shooting film on a Canon AE-1 Program with a Tamron 90mm Macro SP lens. Until recently, the lens worked perfectly, but all of a sudden it won't focus farther than 10ft. To my knowledge it ...