The Pentax D FA 15-30mm f/2.8 ED SDM WR is a fast-aperture ultra-wide zoom lens designed for full-frame Pentax DSLRs. Key features include:
Great low-light flexibility and depth-of-field control
Fast, quiet autofocus; full-time manual focusing
Eighteen elements in thirteen groups
11-inch minimum focusing distance
Full-Frame Ultra-Wide Zoom. The Pentax D FA 15-30mm offers full-frame coverage, enabling you to capture up to an 111° angle of view.
Fast Aperture. The speedy f/2.8 aperture allows great low-light flexibility and depth-of-field control.
Supersonic Drive Motor Autofocus System. This system provides fast, nearly silent autofocus performance for still and video shooting. It also offers full-time manual-focusing capability.
Pro-Grade Build. The thirteen group/eighteen element design features three aspherical elements and three low-dispersion elements that help to maximize image quality by holding chromatic aberrations, distortion, and coma at bay. Pentax boasts of a weather-resistant eight seal design with a “Super Protect” coated front element that repels moisture and dust.