Abstract: A zoom lens system which allows a reduction in size. This zoom lens makes two points at different distances have an optically conjugate relationship, and sequentially includes, from a first conjugate point side at a longer distance to a second conjugate point side at a shorter distance, a first lens unit having a negative optical power, a second lens unit, a third lens unit, a fourth lens unit, a fifth lens unit, and a sixth lens unit. A plurality of lens units of the first to sixth lens units move for zooming, and at least one lens unit of the first to sixth lens units has a diffractive optical element.

Abstract: There are provided a zoom lens system comprising, in order from a more distant conjugate point, a first lens unit of a negative refractive power, a second lens unit of negative refractive power which moves during zooming, third, fourth and fifth lens units, and at least one diffraction optical element.