Variable electric zoom function. The lens has a tiny breathing effect, stepless aperture control and constant F4 aperture. It adopts a lens structure of 15 elements in 12 groups, including 3 aspherical lenses and 3 ED lenses. Internal zoom mechanism, low and easy shifting of the center of gravity Balanced, suitable for motorized gimbal applications. Equipped with a new zoom lever and two customizable function buttons to preset constant zoom speed, focal length or focus