Pentax K-5 Samples

Here the ISO performance of the Pentax K-5 is compared to the Pentax K-7
Pentax K-7. All crops below are shown at 100% and are taken from the highest-resolution and quality JPEG available on each camera. Both ISO and Aperture we set on each camera. Remaining settings were left on automatic, including High-ISO Noise-Reduction which is highly customizable on the K-5. The Pentax K-5 was fitted with a Pentax DA* 50-135mm F2.8 ED (IF) SDM
Pentax DA* 50-135mm F2.8 ED (IF) SDM lens while the K-7 used the Pentax DA* 55mm F1.4 SDM
Pentax DA* 55mm F1.4 SDM.

The Pentax K-5 has a much wider ISO range than its precessor, with one 1/3 stop slower and 3 stops faster ISO. Looking at the crops below the performance of these cameras is really close up to ISO 400. ISO 800 is very slightly better on the newer DSLR. The K-5 takes a noticeable lead from ISO 1600 onwards, showing between 1 and 1½ stops less image noise. Results from the K-5 are extremely usable to ISO 6400 with only a small drop in maximum print sizes. ISO 12800 is usable for a small print. Details get significantly destroyed after that, so ISO 25600 should really be kept for emergencies and very small prints. It is probably best to ignore ISO 51200.

Pentax K-5	Pentax K-7
ISO 80
ISO 100	ISO 100
ISO 200	ISO 200
ISO 400	ISO 400
ISO 800	ISO 800
ISO 1600	ISO 1600
ISO 3200	ISO 3200
ISO 6400	ISO 6400
ISO 12800
ISO 25600
ISO 51200