This lens is an indispensable tool for ambitious photographers. With a 26 - 107 mm focal length (in 35mm film format) it offers the crucial 'plus' of additional range when normal "standard" zooms generally extend to 45 or 55mm. Not only the focal length range is remarkable: with the KAF3 lens mount it relinquishes the classical mechanical autofocus drive for the first time in favour of faster and quieter ultrasonic technology. The lens construction: 17 elements in 12 groups, including 2 aspherical lens elements - guarantors of outstanding pictures. Important details, such as fixed aperture throughout the zoom range provide for excellent control.
Smc DA 17 - 70mm's lens mount is KAF3-type, which means that with K100D, *ist D, *ist DS, and *ist DL, the focus can only be performed manually.