This high-magnification zoom lens is the smallest and lightest in its class, offering ideal cost-performance. a lightweight glass material was used for the first element group – the heaviest group in the optical system – to reduce operational load during autofocus operation. combined with the micro usm, the autofocus is quick and quiet. the slim exterior and smooth zooming makes this lens a delight to use. filter size: 58mm maximum aperture: f/4 - 5.6 with micro usm motor