I think ZOOM LENSES were made for motion picture cameras in 1950 to 60's. To make such lenses, it was very difficult task without super computer then. But some type of shooting, it was good tool and necessity, as sport photographers or folks who did not have time to change lenses. Then, image quality was not there. But today, new optical glass, coating and computer design machine tools, it improved by 1000%. But we used to say, if you were good photographer, USE MANUAL ZOOMING with your arms and legs, don't be too lazy to look for great photo angle and perspective! Also, in general, prime lens has much superior image quality.