Ricoh announces updated Pentax DA* 16-50mm f/2.8 APS-C zoom with new optics and PLM focus motor

posted Wednesday, July 14, 2021 at 6:00 PM EDT

Arriving not long after Ricoh's much-anticipated Pentax K-3 III flagship crop-sensor DSLR, the new HD PENTAX-DA* 16-50mm f/2.8 ED PLM AW zoom lens is a refreshed, high-end versatile zoom lens that's a perfect pairing to this new flagship DSLR. The updated and re-worked Pentax DA* 16-50mm f/2.8 ED PLM AW comes as the successor to the earlier 16-50mm f/2.8 lens, the Pentax SMC DA* 16-50mm f/2.8 ED AL IF SDM, from all the way back in 2007. This new 24.5-76.5mm-eq. constant-f/2.8 zoom lens offers an all-new optical design, updated autofocusing system and enhanced weather-sealed construction. Much like its predecessor, the new 16-50mm f/2.8 remains as part of Pentax's "Star" series of premium, flagship lenses, offering top-of-the-line image quality and performance.

Physically, the new Pentax DA* 16-50mm f/2.8 ED PLM AW zoom lens maintains a fairly similar size and cosmetic design, though it is a bit larger and heavier than the earlier 2007 version. The new model keeps the same approximate diameter of 84mm (3.3in.) and still uses 77mm-sized screw-on filters, but the length has increased to around 117mm (4.6in.) compared the earlier model's 98.5mm (3.9in.) length. The weight has also bumped up a bit to a heftier 721g (1.57lbs.; without lens hood), compared to 565g (1.25lbs.) in the original model.

The lens is also thoroughly weather-sealed, which has been a hallmark feature on several of Pentax's cameras and lenses over the years. Unlike the previous model of 16-50mm lens, which featured a "weather-resistant" design against moisture, this new model earns Pentax's "AW" designation for All-Weather sealing. Essentially, the lens is protected against both moisture and dust. When paired with a similarly rugged, weather-sealed camera body, the rig is capable of withstanding harsh conditions, including dust, dirt, rain and even splashes of water. The lens is capable of operating in very cold conditions, down to -10 degrees C (14 degrees F). The lens also features an SP (Super Protect) coating on the front surface, which helps repel dirt and moisture and makes the front element easy to wipe clean.

As mentioned, the optical layout of this model has been revised compared to the original model, with the lens said to offer clear, sharp image quality performance across the frame. The new 16-50mm f/2.8 lens uses a total of 16 elements -- one more than in the old model -- configured into 10 groups. The lens utilizes several specialized optical elements, including one ED (Extra-low Dispersion) glass optical element, one anomalous glass optical element and two ED (Extra-low Dispersion) aspherical glass optical elements, which all work to minimize chromatic aberrations across the lens's zoom range. Additionally, the use of multi-layer HD Coatings on the lens elements, which Pentax states reduces the average reflectance for visible light to less than 50% of that from using conventional multi-layer lens coatings, helps combat flare and ghosting when shooting in difficult lighting situations.

Overall, Pentax states that the updated optical design of this new lens will offer improved resolving power to "accommodate the super-high-performance digital cameras of the future." Digital camera sensor resolutions have certainly come a long way in terms of megapixel count and overall image quality performance since the first Pentax 16-50mm f/2.8 lens from 2007 -- not to mention their burst-shooting specs and focusing capabilities, as well. It's easy to see that his new zoom lens makes an ideal pairing with the recent Pentax K-3 III, complete its new 25MP APS-C sensor and updated AF system. Plus, this lens's newer, more modern AF system, which we discuss more down below, should make it more capable for high-speed, faster shooting scenarios and faster-shooting cameras. It's pure speculation on our part, but we can't help but wonder if Pentax has higher-resolution and/or even higher-performance APS-C cameras in mind for the future.

When it comes to autofocus, this is another key area of improvement for the 16-50mm f/2.8 PLM lens compared to the original model. As the naming suggests, the new lens no longer uses the supersonic direct-drive motor (SDM) but rather, utilizes a newer, quieter "PLM" motor, or pulse motor, to drive the focusing mechanism. Similar to Nikon's pulse-motor-based "AF-P" lenses, these Pulse motors are essentially stepping motors and the new Pentax 16-50mm f/2.8 PLM lens should offer smoother, faster and quieter AF performance compared to earlier SDM lenses. Further, the optical layout is designed in such a way as to have a smaller and lighter focusing group, which further enhances the speed and precision of the lens's AF system. Overall, the pulse motor design, much like other STM or stepper-motor-based lenses, allows for fast and quiet AF operation, making this new Pentax lens a great option for both stills and video.

Further enhancing the lens's appeal for video, the new 16-50mm f/2.8 uses an electromagnetic aperture control*, allowing for smooth automatic aperture adjustments for exposure control. When filming, the aperture will smoothly adjust as exposure change when using automatic exposure control. The aperture control is also designed for quiet operation, much like the focusing motor, so as to not introduce unwanted operating noise while recording video.

* The lens features the KAF4 mount and is compatible with electromagnetic diaphragm control. Electromagnetic diaphragm control is available in combination with PENTAX K-3 Mark III, PENTAX K-3 II, PENTAX K-3, PENTAX KP, PENTAX K-70, PENTAX K-50, PENTAX K-S2, PENTAX K-S1, PENTAX K-1 Mark II or PENTAX K-1 camera bodies.

Additional features of the new Pentax 16-50mm f/2.8 lens include a 9-bladed circular aperture diaphragm for natural and smooth bokeh performance, a 0.3m (0.98ft) minimum focusing distance and a Quick-Shift Focus System to allow for easy manual focus override after AF operation.