Thanks to its large-aperture design, it provides a large maximum aperture of F2.8 at all focal lengths from 70mm to 200mm
Coupled with other PENTAX-original lens-coating technologies — such as the newly developed Aero Bright Coating II assuring exceptionally low reflectance, and the high-grade HD Coating — it produces extra-sharp, high-contrast images free of flare and ghost images, even under demanding lighting conditions such as in backlight. In addition to four Anomalous Dispersion Glass elements and two ED (Extra-low Dispersion) Glass elements, its optics includes a pair of new Super ED glass elements to effectively compensate chromatic aberration over the entire zoom range and deliver crisp, high-resolution images with edge-to-edge sharpness.
