Pentax K-1 Lab and Test Results on Pentax’s First Full Frame DSLR

These test results were provided by Betternet, TIPA’s (Technical Image Press Association) affiliated testing lab. Edited by George Schaub, a member of TIPA’s Technical Committee.

Camera Handling

The K-1 is Pentax's first full frame sensor DSLR. This compact camera has a width of 137mm and is smaller than, for example, Fujifilm’s X-Pro2, although the depth of the body is larger because the camera needs a little space in its body for the reflex mirror system.

The K-1 offers a lot of function buttons and setup dials: one dial is located near the shutter release button; one is on the back; and a third wheel is located on top. The dial on the top offers direct access to additional functions and parameters, such as changing HDR modes, activating Wi-Fi settings and selecting Crop modes when using lens systems which where designed for APS-C sensor cameras.

The large mode dial on the left hand side on the top offers standard exposure modes as well as additional automatic modes and five user-defined modes. All this makes for a very configurable camera.

The camera has a large and bright optical SLR viewfinder and offers live preview on the LCD screen. This screen has an innovative swivel mechanism which allows the user to rotate the screen 90 degrees upwards, 45 degrees downwards and 35 degrees to each side. The swivel mechanism looks a little strange but is actually quite robust. Actually, the whole camera has a very robust feel to it. It is sealed and can be used outdoors even under heavy rain or in the snow.

The Pentax K-1 has an integrated image stabilizer that will work with every lens attached to the KAF2 mount. It is a 5-axis stabilizer that worked very well during our test. Pentax specifies a 5 EV stop capability, which we feel is a little optimistic, but we shot images with 1/5 and 1/6 second exposures without a tripod and got very good results (Note: Tests where done with the 43 mm lens). The sensor shift mechanism is also use for dust removal and for the “pixel shift” images.

The new Pentax uses a fast AF system which showed a very good performance in our tests. It uses 33 AF sensors (including 25 cross type sensors) and is highly configurable. Three center AF sensors are used for high-speed lenses with f/2.8. For manual focusing the camera offers a magnifier function and focus peaking.

The camera offers additional photo modes and special features. “Astro Tracer” is used for long time exposure shots of the sky and stars. An integrated GPS system can also be used to record geo data and to integrate this information into the EXIF data of the images.

Another special feature is the “HDR Capture” function. The camera can record several images with varying exposure settings and create a combined image with high dynamic range. The user can set up the exposure differences and the camera will align and combine these images to HDR images. With “Pixel Shift” the camera offers a special mode to shoot 4 images with a slightly moved sensor during this sequence and combines these images to a high-resolution image. However, this is done to prevent moiré effects; the resulting image is still 36MP instead of the higher res “pixel shift” images taken with the Olympus OM-D E-M5 II.

The Wi-Fi function is very helpful. It can be used for wireless image data transfer or for remote shooting. It is also very useable and Pentax offers apps for Android (4.4 and higher) and iOS for free.

Image Quality Tests

Color: The Pentax K-1 showed a nice performance in the color tests. Like nearly all Pentax SLRs, the default setting for colors is “Bright”, so the camera creates highly saturated JPEG images. Our tests are done in default settings so the Pentax reproduced the GretagMacbeth chart with a saturation of 107.8 percent and some exaggerated nuances. These boosted colors are the reason for the slightly higher color error level, while all other colors are reproduced very well. Skin tones are very realistic. Changing color setting to a more natural or standard setting will reduce this higher saturation look.

Sharpness: The camera showed an excellent performance in the resolution tests. The very high sensor resolution is translated into visible image details. The test chart was reproduced with 4403 of 4912 lines per picture height, which is a very good result. (Note: Using the pixel shift mode offered by the Pentax K-1 we got results that were higher by 150 lines per picture height).

Images have a sharp and crisp look. The camera assists with a little sharpness filtering, but the result is not at all exaggerated.  

Noise: Up to ISO 6400 the Pentax showed a very good performance in the noise tests. The luminance noise stays below 1.0 percent and color noise is very discreet. Starting at ISO 12,800 the luminance and color noise rise drastically. The highest ISO speed settings of the K-1 should be called or indicated as additional “High ISO modes” or similar, because the color noise gets really extreme. At ISO 204,800 mode the luminance noise factor is 9.17 percent (very high). The color noise spectrum in these images is extremely smoothed by filter processes and image details get really blurred.

The dynamic range results are similar to the noise results. The camera achieved a maximum of 11.3 f-stops and keeps this high level in lower ISO settings up to ISO 3200. In images taken with higher speeds, dynamic range drops drastically to as much as 2.9 f-stops. In these higher modes the test software ImaTest isn't able to detect the single pattern of the gray scale pattern due to the smoothed and blurred images.