Not just for stills: Affordable Pentax K-70 boasts full-time movie autofocus and better aperture control





For a while now, there's been a tradition around Pentax DSLR launches. As each new model lands, the Pentaxian faithful have taken a little while to absorb all the details, and then a vigorous debate has kicked off about its video feature set. With the launch of the Pentax K-70 today, perhaps that debate has taken one step closer to its eventual end.

With earlier launches, there have been two main camps in the video debate. On the one hand are those decrying the new model's lack of certain features like full-time AF during capture, mechanical image stabilization for video capture as in earlier Pentax DSLRs, and clean HDMI output. On the other are those for whom video has been seen as an unnecessary waste of development resources.

Now, the Pentax K-70 is here alongside a brand-new lens, the HD PENTAX-DA 55-300mm F4.5-6.3ED PLM WR RE zoom. Both camera and lens have clearly been made with movie capture in mind, and they allow features never before seen in a Pentax DSLR. Perhaps the key difference for our money is the addition of full-time autofocus during movie capture, something that's achieved thanks to a hybrid autofocus system driven by on-chip phase-detection autofocus pixels on the K-70's brand-new 24-megapixel image sensor.

There's also a new electromagnetic aperture control mechanism which provides for quieter, smoother aperture control during video capture. This feature is thus far specific solely to the new HD PENTAX-DA 55-300mm F4.5-6.3ED PLM WR RE zoom lens, and works only with the K-70, K-1, K-3 II, K-S2 and K-S1 camera bodies, with all but the K-70 also needing a firmware update for compatibility. Older bodies including the flagship K-3 are apparently not compatible with this optic, and we don't yet know if that will remain the case or if future firmware updates could bring additional compatibility.

The new 55-300mm lens is interesting for a couple more reasons, too. It's the first Pentax model to use a pulse motor -- as indicated by the letters PLM in the name -- which is said to allow for 8.3 times faster focus operation at the wide end of the zoom range, and 1.7 times faster at the telephoto end. (Both figures being a direct comparison against the earlier HD PENTAX-DA 55-300mm F4-5.8ED WR lens.) It's also the second retractable, interchangeable zoom lens released by Pentax, after the earlier HD PENTAX-DA 18-50mm F4-5.6 DC WR RE lens. The retractable design allows a length of just 3.5 inches when stored, a full 0.9 inches (20%) shorter than the earlier, non-retractable version. Barrel diameter has increased by 0.2 inches (7%), and weight is just 0.1 ounces (0.5%) more than that of the earlier model.

But there's plenty more to the story of both this new lens and the Pentax K-70 DSLR. For much more info, be sure to read our just-published Pentax K-70 preview!

Priced at US$650 or thereabouts body-only, the Pentax K-70 will be sold in black and silver versions in the US market. A planned availability date has not yet been disclosed, but will be announced at the start of July. A kit with 18-135mm lens will also be sold, priced at US$900. The HD PENTAX-DA 55-300mm F4.5-6.3ED PLM WR RE zoom lens will be available separately from early July for US$400.