Pentax's new K-1 Mark II arrives some two years after the original -- that seems to be the general update cycle for all but the entry-level models -- with only two real enhancements. Even those are made possible by a single hardware change. But these updates may possibly mean a big improvement for people who need better low-light quality or who use Pentax's Pixel Shift Resolution mode. Otherwise, it's identical to its predecessor in all ways but the name badge.
The price has gone up a little. When the K-1 launched in April 2016, the body cost $1,800 and in the interim rose to $1,900. Now it will cost $2,000 when it ships in April 2018, or $2,400 for a kit with the 28-105mm f3.5-5 lens. ($2,000 is about £1,450 or AU$2,600 converted, with real UK and Australian prices TBD.)
Pentax inserted a processing accelerator in the image pipeline between the sensor and the image processor that "optimizes" the data. Since noise-reduction quality is limited by processing time -- the more time you devote to it, the better it is -- the accelerator allows for improved noise reduction. The result is a claimed native sensitivity of ISO 819,200.
Cameras such as thedeliver higher max sensitivity in their expanded ranges, such as that camera's ISO 3,280,000. But the highest claimed native sensitivity we've seen in a full-frame camera has been (I believe) ISO 204,800. Most are typically ISO 25,600, give or take a fraction of a stop. In effect, the native sensitivity usually tells you how well it delivers clean images in low light, while the expanded tells you how far it can be pushed and still deliver a recognizable image. I think of the latter as the desperation range: You don't want to use it unless you're absolutely desperate.
So, essentially, Pentax is claiming it offers a five-stop improvement in low light over typical competitors, and a two-stop improvement over the K-1 (rated at ISO 204,800).
Now, the Pentax K-1 has great photo quality, but I'd say the best you could do without losing significant color and dynamic range is ISO 51,200. But two additional usable stops to ISO 204,800 is still really useful if you shoot in very low light or sports in poor light.
The new circuitry also improves Pixel Shift Resolution mode, Pentax's feature for creating higher-resolution images by combining automatic captures with the sensor slightly offset in several directions. PSR II uses color data to deliver to improved detail and color in the final image, but most notably, adds the ability to shoot handheld with PSR rather than requiring a tripod. That's big if you use it, though it remains to be seen how good it is.
Probably the best news is for existing K-1 owners: From May 21 to Sept. 30, Ricoh Imaging Americas is offering an upgrade service for $550, at least in the US and Canada. It has to be sent to one of two US service centers, Precision Camera or Sun Camera. In addition to adding the accelerator electronics, they'll rebadge your camera with the new logo.
But before you get all excited, based on the specs it looks like the battery takes a hit from the accelerator, dropping from a rating of 760 shots in the K-1 to 670 in the Mark II. And Pentax didn't update some of the aspects I complained about, including the pokey autofocus system and weak image stabilization.