Pentax K-50 Review
Our field tests as well as tests performed by other web sites (i.e. DxO mark) have confirmed that for all practical purposes, the K-50's image quality is identical to that of the K-30, which we know to be excellent. Until recently, the K-30 had best-in-class image quality; the Nikon D5200 has pushed ahead somewhat with its 24 megapixel sensor.
Due to the close similarity between the K-30 and K-50, we recommend that you read our analysis of the K-30's image quality for more insight into what you can expect from the K-50.
There is only one subtle difference between the K-50 and its predecessor as far as sensor specifications go. Pentax increased the maximum sensitivity setting in the K-50 to ISO 51,200, up from ISO 25,600 in the K-30. Therefore, we felt obliged to perform a quick test to see what having this extra stop of sensitivity would mean in practice. The images below are 100% crops of unedited JPEGs from the K-50; noise reduction was left at the default (auto). Click on any thumbnail to enlarge, and use the lightbox to scroll through them.
The test shows that the K-50 produces very clean files up to ISO 800. At ISO 1600 and 3200, noise is apparent but still manageable. The noise levels grow at ISO 6400 and 12,800, though even at these high sensitivty settings, most color detail is preserved. If you boost the sensitivity to ISO 25,600, however, a significant drop in detail can be observed. An even bigger drop happens at ISO 51,200, and thus we feel that for all practical purposes, this high sensitivity setting should be avoided. It may be wiser to shoot in RAW mode at ISO 6400 or 12,800 and deliberately underexpose than to use ISO 25,600 or 51,200.
We therefore conclude that presence of ISO 51,200 doesn't do you much (if any) good, except for bragging rights perhaps.
The K-50's 77-segment matrix metering system performed well during our practical tests. You can expect the K-50 to deliver accurate exposure, though we observed a slight tendency to overexpose in bright outdoor situations. In addition to the matrix metering mode you can also use center-weighted or spot metering.
JPEG Image Engine
As we mentioned earlier, the K-50 allows you to customize the appearance of its JPEG files via a "custom image" menu. In addition to choosing from one of 11 presets, you can manually tweak the following parameters:
- High-key/low-key filtering
- Color filter (B&W only)
- Toning (B&W, muted, and bleach bypass only)
The default preset, "bright", delivers pleasing images with warmer color tones compared to the "natural" preset.
Depending on your shooting style, we recommend either the "bright", "natural", or "vibrant" presets.
The K-50 is of course capable of capturing photos in a 12-bit DNG RAW format. Shooting in RAW gives you complete control over your photo at the expense of a longer post-processing time, and you're also able to extract more detail than you would from a JPEG. Note that if you decide to use the Pentax desktop software bundled with your camera, you can apply any of the 11 custom image settings shown above retroactively.
Most upper enter-level/mid-range DSLRs offer 14-bit RAW (which enables a slightly wider dynamic range), so the Pentax is a bit behind the competition in this respect.
All lenses mounted on the K-50 will be stabilized thanks to the in-body shake reduction system. It is important to note that in order to get reliable stabilization, you must give this system about half a second to arm by half-pressing the shutter button or operating the autofocus before releasing the shutter.
The in-camera stabilization system compensates for about 3 stops of light, meaning that you can get blur-free hand-helds at shutter speeds as slow as 1/10s with the 18-55mm kit lens.
Through tests with the K-50 and other Pentax bodies we have found that the sensor-shift shake reduction mechanism is just as effective as in-lens shake reduction unless you are using an extreme telephoto lens. The only key difference between the two systems is that the viewfinder is not stabilized with sensor-shift shake reduction (the live view display is, however).
The K-50's shake reduction system also enables dust removal, which works by vibrating the sensor in an effort to shake off dust. The K-50 uses the older style "DR I" system, which is rather loud and clearly audible when running (unlike the shake reduction itself). Higher-end Pentax cameras use an ultrasonic dust removal system that isn't audible.
The K-50 sports a plethora of other features to expand your creative possibilities and ensure the best possible image quality. These features include in-camera shadow/highlight correction (described in more detail here), artistic filters, multi-frame HDR, lens distortion correction*, and chromatic aberration correction*. The in-camera HDR mode combines a series of 3 images in order to brighten areas that would otherwise be overexposed, and vice-versa. It is possible to use this mode without a tripod, though the results will be better with one.
Three HDR intensities can be selected; all but the weakest introduce an easily-discernible halo effect around edges.
*in-camera lens corrections are only supported by Pentax DA, D FA, and FA limited lenses. Photos third-party lenses such as those from Sigma and Tamron will need to be corrected during post-processing.
Image Quality Verdict
If you're looking for a camera with great image quality, the K-50 will get the job done. Its performance is still among one of the best available in an APS-C camera.
As we mentioned earlier, please refer to the image quality page of our K-30 review for more technical details on the K-50's image quality.