Pentax K-3 Review

Ultimately, image-quality is what makes a camera worth buying. For a digital SLR, it greatly depends on the lens used. While image-noise, exposure, color, white-balance and contrast are properties of the camera, distortion, vignetting, chromatic aberrations are properties of the lens. Sharpness depends on the weakest link. That is, a camera cannot capture more details than its lens lets through. Conversely, it is possible that a lens transmits more details than the sensor can capture.

The Pentax K-3 produces exceptionally low-noise images, matching the K-5 IIs at low ISOs. Up to 400, images are ultra-clean and usable to the maximum print-size from a 24 megapixels image. Noise starts appearing at ISO 800 where the K-3 forcibly starts noise-reduction at the sensor-level. Additional NR can be added but does not improve things.

ISO 1600 shows more evidence of softening from noise-reduction which is the point where the K-3 falls behind the stellar performance of the K-5 IIs
Pentax K-5 IIs. At ISO 3200, things are a tiny bit softer but moderately large prints are still possible. This is an excellent performance compared to all digital cameras but the Pentax K-5 IIs.

Noise becomes clearer at ISO 6400, eating at the finest details. Still, images from the Pentax K-3 are extremely usable for mid-sized prints at ISO 6400. By ISO 12800, print sizes are more affected, yet this DSLR can still pull off some nice prints at that sensitivity.

ISO 25600 and 51200 are quite noisy and soft. However, with 24 megapixels of resolution, small prints are still possible at 25600, just not at 51200 anymore. APS-C DSLRs rarely feature such a high ISO and technology has not caught up yet.

The Pentax K-3 offers Multi-Segment, Center-Weighed and Spot metering modes. The new 86K-pixels metering system brings OVF metering inline with Live-View, removing a source of frustration from previous Pentax digital SLRs. This new metering system is excellent and produces well-balanced exposures. It will clip highlights only fractionally more often than the K-5 IIs while producing generally brighter images as a consequence.

Highlight Correction works extremely well to expand the dynamic-range and is now available at all sensitivities. It should be turned on permanently to avoid clipping highlights more often. Since this setting affects exposure, it cannot be changed while converting RAW files, contrarily to Shadow Correction. This latter setting is particularly well implemented and results in a less dull look than usual.

Dynamic-range of the Ricoh Pentax K-3 is good and inline with similar high-resolution DSLRs. It just does not match the class-leading dynamic-range of the K-5 IIs. Still, only a few APS-C cameras can match the K-3.

The Pentax K-3 shows excellent hue accuracy. Natural color mode is very close to reality. Adjusting Saturation to +1 makes it even better. Hue is one step off by default, so pushing it to +1 too makes colors nearly perfect. This DSLR has an impressive amount of image-parameters, including distinct tone-curves for highlights, mid-tones and shadows. This lets more dynamic-range be captured while maintaining contrast where it is desired. Bright color mode, which is the default, is great too and gives image more punch with extra saturation and contrast.

Sharpness is controlled in 9 steps along a Standard, Fine or Extra Fine scale. The lowest setting is very soft on any scale while the highest setting is rather sharp. The Pentax K-3, due its lack of an anti-alias filter, is sharper than most DSLRs. It therefore requires less sharpening and shows artifacts quicker. The Fine scale sharpens fine details without sharpening noise and is completely artifact free at +1 which is the optimal setting.

Digital cameras have traditionally used anti-alias filters to avoid moire which is an artifact that may occur when taking pictures of extremely fine textures. This compromise avoids the artifact almost entirely for full-resolution images at the expense of critical sharpness. Now, with this one and a handful of other digital cameras, these artifacts could appear.

The unique feature of the Ricoh Pentax K-3 is Anti-Alias Filter Simulation achieved by deliberately moving the sensor during exposure using the Shake-Reduction system which as designed to avoid sensor-shake in the first place. Oh, the irony!

The great news is that Anti-Alias Filter Simulation works exactly as advertized. It reduces moire by blurring the image slightly. Keep in mind that it does eliminate moire completely and that diffraction is a perfect alternative. In other words, as shown below, stopping down to F/13 removes moire just as well.

Anti-Alias Simulation

Off	Weak	Strong
F/1.8 F/2 F/2.4 F/2.8 F/3.5 F/4 F/4.5 F/5.6 F/6.7 F/8 F/9.5 F/11 F/13 F/16

Pentax provides an excellent interface for changing image parameters. The most significant feature is a preview which is dynamically updated whenever an image parameter is changed. A nice detail is that any setting that is not at its default value is shown yellow. Settings at their default values are shown in green. A hexagonal shape, representing the color-space, shows how colors are affected by image parameters.

The K-3 introduces a new Multi-Light-Source option to the already sophisticated AWB of its predecessors. The choice for strong or subtle correction from warm lighting remains too. AWB performs well on the K-3. While not perfect, it does render colors more neutral than the majority of digital cameras. Custom WB is spot on though.

In operation, the Pentax K-3 is always very responsive. Instant review is now immediate which is the only aspect where the K-5 family lags. The performance of the K-3 is characterized by the following measurements:

• Power On: ½s. Very good.
• Power-On to First-Shot: 1s. Excellent.
• Autofocus: Usually under ¼s, often ½s in low-light, sometimes longer. Very good to average.
• Shutter-lag: Instant. Excellent.
• Shot-to-shot: ½s. Below average for high-end.
• Playback: Immediate to enter or exit. Fantastic.
• Video: Just under ½s to start or stop. Good.
• Power-Off: Instant. Great.

The new SAFOX XI autofocus can be extremely fast but it not always so. When light levels are moderately low, the K-3 slows down to adjust focus. It is unclear if lenses are holding SAFOX XI back but, while fast, the K-3 does not compare well with high-end DSLRs from other brands. Sensitivity is top-notch though and the K-3 eventually manages to lock focus even near darkness.

Focusing accuracy is superb and this DSLR rarely locks focus incorrectly. Compared to the K-5 IIs, both speed and sensitivity remain the same. The AF system is obviously more sophisticated can better at tracking but even so it tends to play catch up with subjects in motion, rather than keep them locked in focus.

Image playback is ultra-fast. Entering and exiting Playback mode is instant, as is switching between images. Even zooming-in and switching between images while zoomed-in is impressively fast. The K-3 is Shooting-Priority and tapping the shutter-release instantly returns it to Capture mode.

Although there is no formal procedure for measuring the performance of image stabilization, we can say that the Shake Reduction system in the K-3 appears to be normally effective to around 2.5 stops. Battery-life is notably below average with 560 shots-per-charge according to the CIPA standard with 50% flash use. This rises to 720 shots-per-charge when not using the flash.

The Pentax K-3 brings an unprecedented feature-set to digital cameras. Having a unique Anti-Alias Simulation plus 4K Time-Lapse Video on top inheriting most features from the K-5 IIs
Pentax K-5 IIs makes it an incredibly capable and versatile camera. Packing so many features also means a new height of complexity.

As Ricoh's first DSLR, the K-3 delivers a powerful statement. Its 24 megapixels APS-C CMOS sensor boats a class-leading sensitivity range of 100 - 51200 and very fast 8.3 FPS continuous drive. The new 27-point SAFOX XI autofocus system aims for professional photographers who work with fast action.

Image-quality of the K-3 is excellent. At low ISO, it matches the performance of the K-5 IIs while delivering 50% more megapixels. This advantage disappears as sensitivity rises above ISO 800 which leaves the K-5 IIs as the very best performing APS-C DSLR on the market. The Pentax K-3 is just behind but still among the top-of-the-class.

Exposure is extremely reliable and color rendition is superb. White-balance is very good and highly flexible. The Anti-Alias Simulator works well, giving photographers the choice between ultimate sharpness and safety from moire artifacts, an completely unique proposition.

Autofocus has class-leading sensitivity. It can lock focus very fast but is unable to do so with the consistency of its top competitors. This puts the K-3 slightly behind for action photography while it compensates well in other areas. Performance of the Pentax K-3 is impressive in many areas. The camera is truly responsive with only shot-to-shot speeds and battery-life falling behind current DSLRs.

Ricoh is sticking with the Pentax formula when comes to its design philosophy which is certainly the right thing to do. The K-3 remains extremely ergonomic and is brimming with helpful features such as Automatic Horizon Correction, Digital Preview and its bright 100% coverage viewfinder.

Ultimately, the Pentax K-3 is an excellent camera which delivers high image-quality suitable for very large prints in a tough weather-sealed and freezeproof body. Its unmatched feature-set opens up creative possibilities like no other DSLR.