The Pentax DA 17-70mm F4 AL IF SDM Lens  is a high-quality fixed-aperture f/4 lens designed exclusively for use with digital SLR cameras. This lens brings together advanced optical technologies.
It offers a versatile wide to medium-telephoto zoom range, and allows for a wider range of shooting applications over the more standard zoom lenses.
This lens comes equipped with the SDM focusing system, which assures smoother and quieter auto-focusing operation by using a built-in supersonic motor. Since this lens only has electrical contacts to communicate between the lens and the camera, autofocusing will only be possible with DSLR cameras that support SDM (e.g. K10D, K20D, K100D Super, K200D, and later models). When mounted on older Pentax digital SLR camera bodies, only manual focusing will be possible.
Note! Not recommended for 35mm film SLR cameras, and digital SLR cameras that don't support SDM feature.
Ultra-Wide to Medium-Telephoto
Equivalent focal length of 26-107mm in 35mm format, when used with digital SLR cameras.
High Optical Performance
ED and aspherical elements compensate for chromatic and spherical aberration.
Exclusive Digital Design
The image circle of the lens has been created to match the smaller image recording area of digital SLR cameras. This ensures precise optical performance ideally suited to the camera's digital imaging characteristics.
SP (Super Protective) coating made of a special fluoride compound has been applied to the front surface of the new lens through the use of a unique evaporation process. As a result, the lens offers excellent water- and oil-repellent performance and makes for easier cleaning should the lens be accidentally smeared with fingerprints or cosmetics.
Quick-Shift Focus System
The Quick-Shift Focus System allows to instantly shift to manual focus once the subject is captured by AF.
Updated Lens Mount
Features the Pentax KAF3 mount, which incorporates electrical contacts to drive the built-in supersonic motor used in autofocusing operation. 1
The smc Pentax DA 17-70mm f/4 AL [IF] SDM wide angle zoom lens offers both wide angle and extra zoom for a broad range of shooting applications and delivers the highest level of optical quality.
The lens's SDM autofocus motor compliments current Pentax DSLRs with fast, accurate, quiet focus.
Bringing together advanced optical technologies, including aspherical elements, original Pentax SP (Super Protect) lens coating, along with a Quick-shift Focus System, this new interchangeable DSLR lens is superior in contrast, clarity and edge-to-edge sharpness.
Quick-shift Focus System
Super Protect Coating
Only compattible with cameras with SDM control