Canon and Nikon are the two big names in DSLR photography, so it’s easy to forget that Ricoh Imaging is still hanging on in there with some interesting, Pentax-branded APS-C DSLRs. Perhaps more importantly, its flagship model is the well-regarded, full-frame K-1.
Launched in February 2016, this is the only full-frame Pentax DSLR released to date. Two years on, Ricoh Imaging has launched a new a new version with an accelerator unit for better high ISO performance and a new Dynamic Pixel Shift Resolution mode, together with improvements to its autofocus algorithms. It's also adding a steady stream of new Pentax lenses for this larger full frame format.
These are not major changes, then, but they do represent some useful improvements to a camera that’s already an interesting and strong rival to other, better-known, full-frame options. The K-1 Mark II’s key selling points are its 36.4MP sensor, its powerful Shake Reduction II system and its sturdy build. It also has some interesting and innovative controls, including a scissor-action articulating rear screen and extended exposure modes.
- Sensor: 36.4MP full-frame CMOS, 35.9 x 24.0mm
- Image processor: PRIME IV
- AF points: 33-point phase detect AF (inc. 25 cross-type)
- ISO range: 100 to 819,200
- Max image size: 7,360 x 4,912
- Metering zones: 86k-pixel RGB sensor
- Video: Full HD at up to 60i/50i/30p/25p/24p
- Viewfinder: Optical, approx 100% coverage
- Memory card: 2x SD/SDHC/SDXC (both UHS-I)
- LCD: 3.2in vari-angle, 1,037,000 dots
- Max burst: 4.4fps
- Connectivity: Wi-Fi, GPS, USB 2.0
- Size: 136.5 x 110.0 x 85.5mm
- Weight: 1,010g (with battery and memory card)
While the K-1 Mark II's 36.4MP sensor isn't as high in resolution as those inside other full-frame models like the Nikon D850 and Canon EOS 5DS, this pixel count and a price tag well under £2,000/$2000 means that it still offers a lot of image quality for the money. In its price range, the K-1 Mark II is competing with the 24-megapixel Nikon D750 and Sony A7 III, as well as the 26MP Canon EOS 6D Mark II.
The new accelerator unit effectively gives the K-1 Mark II a processing boost to deliver better image quality at high ISO settings. Indeed, this camera now has a impressive maximum sensitivity of ISO 819,200, although quite whether it can deliver quality results at these settings we'll see later in this review.
Pentax was an early pioneer of in-body image stabilisation systems, but the SR II (Shake Reduction II system) built into the K-1 Mark II does much more than control camera shake. It’s also used to provide anti-aliasing simulation, moving the sensor by a microscopic degree during the exposure to give the effect of an optical low-pass filter.
Low-pass filters are used on most cameras to slightly blur ultra-fine detail and prevent moiré or interference effects with fine patterns or textures, which show up as false colour effects under magnification. A number of cameras – the K-1 Mark II included – either does without this optical low-pass filter, or has a separate cancelling filter alongside, so that fine detail is slightly crisper. With this camera, if you’re shooting a subject where moiré is a problem, you can enable the anti-aliasing option.
Pentax’s SR II mechanism can move the sensor in response to other shooting conditions. It can, for example, be used to automatically straighten slightly skewed horizons, or for minute adjustments to the composition when the camera is on a tripod and the movement required is too fine for a regular tripod adjustment.
One of the system's most amazing tricks is its ASTROTRACER mode, where the camera uses the sensor-shift mechanism in conjunction with its built-in GPS sensor to render stars and other stationary subjects in the sky without any streaking during long exposures. The length of the exposure is limited because the sensor shift mechanism will eventually run out of movement, but it’s still a clever way of capturing star fields and other celestial objects without the need for a motorised mount.
For regular photography, however, it’s the Pixel Shift Resolution System II mode that’s likely to be most interesting. Here, the camera takes four exposures in quick succession, moving the sensor by one pixel at a time so that each pixel captures full red, green and blue colour data (rather than this data having to be interpolated from neighbouring pixels, which is how it ordinarily works). You need a tripod for this to work best and a reasonably static subject, but in theory it should produce even sharper fine detail and fewer colour artefacts.
The Pentax K-1 Mark II, however, gets a new Dynamic Pixel Shift Resolution mode that's designed for handheld use. This works differently, combining four images taken in quick succession before merging these into one, in order to deliver superior detail, noise and overall image quality.
Other features include a weather-sealed magnesium alloy body with 87 weather seals, together with an optical viewfinder with approximately 100% coverage and an interesting articulated rear screen that allows up-and-down tilt and a degree of side-to-side movement too.
The Pentax K-1 Mark II uses the same 33-point SAFOX 12 system as its predecessor, though with improved AF algorithms for tracking moving subjects. With no hybrid phase-detect AF system for its live view mode, however, and with only Full HD video capability, the K-1 Mark II is not going to be a first choice for video specialists.
Thanks to a relatively pedestrian maximum continuous shooting speed of 4.4fps, it’s not a sports specialist either. In this respect, the K-1 Mark II does lag a little way behind its other full-frame rivals, though this burst rate does increase to 6.4fps in its APS-C crop mode when using Pentax’s smaller-format APS-C lenses.
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