Pentax SMC DA 17 70mm F4 AL IF SDM Análisis | 54 Datos comparados

The Pentax SMC DA 17-70mm f/4 AL [IF] SDM review on Photozone highlights this standard zoom lens as a highly attractive "sweet spot" option for APS-C format shooters, offering a versatile full-frame equivalent focal range of 25.5–105mm. On the positive side, the lens boasts exceptionally high build quality with tight tolerances, smooth zoom and focus rings, and an internal focusing mechanism that leaves the front element stationary. It features a unique Super Protect (SP) coating to repel environmental dust, water, and grease, alongside a near-silent Supersonic Dynamic Motor (SDM) that enables very fast autofocus speeds due to a notably short focus path. It also provides an instant manual focus override via its Quick-Shift system during Single-Shot AF. However, the review details a few notable drawbacks regarding its design and functionality. A major con stemming from its ultra-short focus path is that manual focusing is extremely difficult, as tiny physical adjustments to the focus ring cause massive, disruptive shifts in focus. Additionally, unlike some of its predecessors, it drops the old mechanical AF drive screw entirely, meaning it lacks autofocus support...

The Pentax 17-70mm f/4 AL IF SDM SMC DA is a solid upgrade to standard kit lenses, offering a versatile 26-105mm equivalent field of view and a constant f/4 maximum aperture. On the positive side, the lens delivers exceptional center sharpness even when shot wide open, achieving its "tack-sharp" peak performance at 50mm and f/8. Additionally, corner shading (vignetting) is minimal and practically negligible at most settings, while the lens-driven Supersonic Drive Motor (SDM) ensures autofocus operation is incredibly fast, snappy, and nearly silent. However, the lens has several notable drawbacks outside of its optimal focal ranges. Chromatic aberration is a significant issue, exhibiting noticeable purple fringing in high-contrast corners at focal lengths wider than 35mm and when stopping down at the 70mm telephoto end. Geometric distortion is also ever-present, cycling from heavy barrel distortion at wide angles to a messy blend of pincushion and barrel distortion by 33mm. Finally, while the build quality is physically robust, manual focus users will struggle due to an extremely narrow quarter-inch focusing ring and a very short 25-degree focus throw that makes precise...

The SMC Pentax-DA 17-70mm f/4 ED IF SDM lens, reviewed by ePHOTOzine, offers a versatile 4.1x zoom range with excellent handling, a firm zoom mechanism, and very good central sharpness that peaks at f/5.6. While the lens is noted for its ability to produce good images in the center, edge performance remains only fair, and it produces severe chromatic aberration with, at times, over 2 pixels of edge fringing.

The SMC Pentax-DA 17-70mm F4 AL [IF] SDM is regarded on Pentax Forums as a versatile, high-performing walkaround zoom lens for APS-C cameras, featuring excellent sharpness across most of the range, strong contrast, and a useful 0.28-meter minimum focus distance. While praised for its image quality, the lens is plagued by common SDM autofocus motor failures that can disable AF entirely, alongside soft performance at 70mm and limited weather-sealing. For detailed user experiences, visit Pentax Forums.