The Pentax K-7 is compared to its predecessor, the K20D, below. All images below are 100% unmodified crops from their respective cameras. Both cameras were set on aperture-priority mode with fixed ISO. Picture style is bright on both cameras. The remaining settings were left on automatic. Images were framed identically on both cameras which were mounted with the Pentax DA 35mm F2.8 Macro Limited lens.

The most significant difference is that the K-7 knows its white-balance much better than the K20D, which leaves too much yellow. The K-7 is still not perfect in this regard, as it removed too much yellow, at least with white-balance correction set to strong in the custom-settings menu. Exposure is identical up to ISO 1600, when the K20D chooses slightly faster shutter-speeds, suggesting differences in actual ISO sensitivities.

In terms of ISO performance, the K-7 shows a slight advantage over the K20D, between 1/4 and 1/2 a stop. Noise is less chromatic with the K-7 than with the K20D. Note both cameras were set to no high-ISO noise reduction which is the default on the K20D but not on the K-7, which defaults to medium for ISO 1600 and up. This may explain why comparisons between these two cameras do not always yield the same conclusion. Here the goal was to compare the least processed output of each camera, since noise-reduction can be applied in software at a later stage.