Abstract: A camera zoom lens system comprising; means for generating and storing a first information signal representing a predetermined position of the first movable lens group, means for generating a second information signal whose value determines a relationship between the respective positions of said first and second movable lens groups, first computing means for deriving from the stored first information signal a third signal representing the position to which the second movable lens group must move so that both lens groups produce an in-focus image of the object at infinity, second computing means responsive to the first and second information signals for generating a correction signal which when combined with the third signal produces an output signal representing the position to which the second movable lens group must move so that both lens groups will produce an in-focus image of an object at a specified distance, third computing means responsive to the correction signal and the third signal for generating a