Andy Westlake tests Pentax's latest fully featured mid-range DSLR with in-body image stabilisation
Pentax K-70 – Pixel Shift Resolution
The Pentax K-70 includes the Pixel Shift Resolution system previously seen on the K-3 II and full-frame K-1. In almost all cameras, the light-sensitive pixels capture red, green or blue light, and a full-colour image is built up using a clever process of interpolation between them. But this can give rise to softness and artefacts when examining images closely at the pixel level.
Pixel Shift Resolution mode, however, combines the information from four exposures that are made by moving the sensor by precisely one pixel between each in a square pattern. This allows the sampling of full-colour image information at each pixel location in the final image, which gives much-improved image quality. The camera has to be fixed on a tripod for it to work, but like the full-frame K-1, the K-70 includes a motion-correction setting that takes into account subjects that move between the exposures.
In practice, the system works well, although naturally you’ll need a good lens to make the most of it. Images taken in Pixel Shift Resolution mode show visibly finer detail, and the motion-correction setting dramatically reduces image artefacts on moving leaves or water, although it doesn’t quite eliminate them. Because of this, it’s still best suited to static subjects such as still life or architecture.