The 12 megapixels Nikon D300 is compared to the 15 megapixels K20D. All images below are 100% unmodified crops from their respective cameras. Both cameras were set on aperture-priority mode with fixed ISO and tungsten white-balance. The remaining settings were left on automatic. The D300 had the Nikkor 18-135 F3.5-5.6 lens while the K20D had the Pentax DA* 50-135 F2.8.

At the base sensitivity of ISO 100, the images show similar color and noise levels. Preset white-balance is quite accurate on both cameras. As expected from DSLR cameras noise levels are extremely low. The first difference is that the Pentax K20D clearly produces a sharper and more detailed image. The second difference is that the K20D always chooses a brighter exposure. Note that there are exposure inconsistencies between ISO settings which may be due to our lighting getting old.

The Nikon D300 and the Pentax K20D produce very smooth images up to ISO 400. At ISO 800, noise becomes slightly apparent on the D300 but the image becomes softer due to noise-reduction. Next to it, the K20D keeps image details much better but produces more visible noise. The same tendency continues at ISO 1600. At ISO 3200, the Nikon becomes noisier and softer but maintains a good color balance. The Pentax gets even more noisy and colors shift slightly towards yellow. At ISO 6400, things get even worse: the D300 becomes noisier and softer while the K20D becomes noisier and even more yellow. Note that the crops are only one version of the story because both the Nikon D300 and the Pentax K20D have customizable noise-reduction settings. On the D300 the default is Low, while on the K20D the default is Off.