A high-performance, Star-series telephoto zoom lens for use with PENTAX K-mount digital SLR cameras, providing F2.8 maximum aperture over the entire zoom range to deliver outstanding image rendition

1. High-performance Star (^★)-series lens with large F2.8 maximum aperture

This telephoto zoom lens has been developed as a new model of the high-performance Star (^★) series, which assures exceptional image rendition with edge-to-edge sharpness by effectively compensating various aberrations to a minimum. When mounted on a PENTAX K-mount SLR camera body, it provides a zoom ratio of approximately 2.9 times to cover a telephoto range from 107mm to 307mm in the 35mm format. Since it provides a large maximum aperture of F2.8 over the entire zoom range, it is ideal for portraiture with beautifully defocused foreground/background and sports photography demanding high shutter speeds to freeze the action. Its image circle is optimized to cover even the image size of 35mm film-format SLR cameras. As the result, it not only assures brilliant, high-resolution images without compromising the sharpness at edges even when mounted on an existing PENTAX digital SLR camera body, but it is also capable of accepting future models with larger image sensors without modifications.

2. State-of-the-art optical technology

This zoom lens is treated with the newly developed Aero Bright Coating II -- a lens-coating nanotechnology that employs a super-low refractive film fabrication process to assure light reflectance lower than that of the conventional Aero Bright Coating.* By coupling this advanced lens coating with the high-grade, multi-layer HD Coating** that reduces an average reflectance in a visible ray spectrum to less than 50% of conventional multi-layer coatings, this lens effectively reduces flare and ghost images to a minimum even under demanding lighting conditions such as backlight. In its optics, it also features four super-low dispersion glass elements, two ED (Extra-low Dispersion) glass elements, and two Super ED glass elements, which have optical properties similar to fluorite and assure lower light dispersion and more effective compensation of chromatic aberration. As the result, this lens produces brilliant, high-contrast images with edge-to-edge sharpness, while effectively compensating chromatic aberration over the entire zoom range.

* A state-of-the-art, PENTAX-original lens coating technology developed from nanotechnology. It applies a silica aerogel coating layer with uniform porous structure over a regular multi-coating layer to reduce surface reflections across a wide wavelength range and produce crisp, high-quality images.
** HD stands for High Definition.

3. Dustproof, weather-resistant construction

Developed as an AW (All Weather) model, this zoom lens features a dependable dustproof, weather-resistant construction with 13 special seals to prevent the intrusion of water and dust particles into the lens interior. By pairing it with a PENTAX weather-resistant digital SLR camera body, it assures a durable, reliable digital imaging system that performs superbly in demanding shooting settings -- even in rain or mist, or at locations prone to water splashes or spray.

4. Newly installed three-position switch for Quick-Shift Focus System

The lens is equipped with the PENTAX-developed Quick-Shift Focus System, which allows the user to instantly switch to manual-focus operation after the subject is captured in focus by the camera's AF system. In order to improve its operability, a three-position switch is newly installed on this lens, allowing instant switching among QFS/A, QFS/M and MF modes. QFS/A is an autofocus-priority mode, which allows the user to switch to manual-focusing operation only when autofocus operation is completed. QFS/M is a manual-focus-priority mode, which enables the user to switch to manual focusing at any time -- even when the AF system is in operation. MF mode allows the user to instantly switch to manual focusing with a simple twist of the focus ring on the lens. With a choice of three distinctive modes, the user is assured of speedier, more accurate focusing operation for a given subject or application.

5. Other features

1. ・Smooth, quiet AF operation using a lens-installed AF driving motor
2. ・Round-shaped diaphragm to produce a natural, beautiful bokeh (defocus) effect, while minimizing the streaking effect of point light sources
3. ・Focus range limiter to minimize AF operation time by fixing the focus range to one of three sub-ranges
4. ・SP (Super Protect) coating to keep the front surface free of dust and stains
5. ・Detachable tripod mounting with a newly designed anti-falling mechanism

Specifications