The Pentax SMCP-DA 17-70mm f/4 AL (IF) SDM Autofocus Lens is a versatile zoom lens designed specifically for Pentax digital SLR cameras, particularly those with SDM (Supersonic Drive Motor) capabilities. Here are the key features and specifications:

Key Features

Focal Length: 17mm to 70mm, equivalent to approximately 26mm to 107mm in 35mm format, making it suitable for a wide range of photography from landscapes to portraits.

Aperture: Constant maximum aperture of f/4 throughout the zoom range, allowing consistent exposure settings when zooming.

Construction: Composed of 17 elements in 12 groups, including aspherical lenses (AL) that enhance image quality and reduce distortion.

Autofocus System: Utilizes a near-silent Supersonic Drive Motor (SDM) for fast and quiet autofocus, with a Quick-Shift focus system that allows instant manual focus override.

Build Quality: Features high-quality materials with a robust design, weighing approximately 485 grams (17.1 oz), which balances well on camera bodies.

Coating: The front element is treated with Pentax's Super Protect (SP) coating to repel dust, water, and grease, making it easier to maintain.

Filter Size: Accepts 67mm filters.