The development of this new zoom lens was based on the previous smc PENTAX-DA FISH-EYE 10-17mm F3.5-4.5 ED (IF), while conducting a thorough review of lens coatings. The high-grade, multi-layer HD Coating has been applied to the optical elements for high-contrast images with edge-to-edge sharpness and free of flare and ghost images. The exterior has been totally redesigned to match the design of the latest PENTAX K-mount digital SLR models, and also to make its lens hood removable. When mounted on a PENTAX K-1 or PENTAX K-1 Mark II camera body, the photographer can remove the lens hood to produce nearly circular fish-eye images.

HD Coating to enhance imaging power
After a thorough review of lens coatings, PENTAX applied HD Coating — PENTAX’s latest multi-layer coating — to the lens. Compared to conventional multi-layer coatings, this high-performance, multi-layer coating reduces average reflectance in the visible light range by more than 50 percent and improves light transmittance, to minimize the adverse effects of flare and ghost images even in demanding lighting conditions such as backlighting. This zoom lens also incorporates an Extra-low Dispersion (ED) glass element to effectively compensate for chromatic aberration for extra-clear, high-contrast images.

Zoom range covering the fish-eye angle
When mounted on a PENTAX digital SLR camera body, this zoom lens provides a 180-degree diagonal angle of view in the APS-C format at a focal length of 10mm to deliver eye-catching fish-eye images. Since the angle of view shifts dramatically with a slight change of focal length, the photographer can easily create visual expressions typical of an ultra-wide-angle lens, such as exaggerated perspective, deformed subjects and a pan-focus effect to capture the entire image field in focus.

New exterior design to match latest digital SLR models
While retaining the overall size of the original smc PENTAX-DA FISH-EYE 10-17mm F3.5-4.5 ED, this zoom lens features a totally new exterior design, similar to that of the latest DA- and D FA-series lenses. This new appearance also makes it a perfect partner for the newest K-series digital SLR models. Although it is an ultra-wide-angle zoom lens, it has been designed to be extremely compact and lightweight. The removeable lens hood allows for nearly circular fish-eye images* to expand the range of photographic expressions, when mounted on a PENTAX K-1 or PENTAX K-1 Mark II camera body.
^{*When the lens hood is removed with the Crop Function set to FF mode, there may be vignetting and/or lowered imaging performance at the edges of the image field, because the resulting image contains elements outside the lens’s image circle.}

SP Coating to repel stains
SP (Super Protect) Coating, highly repellent to water, grease and dirt, has been applied to the lens’s front surface using a PENTAX-exclusive fluorine deposition process, making it easy to wipe off any stains such as fingerprints. This frees the photographer from worries in outdoor photography.