See these one by one:-Pentax K-r vs. K-x ISO comparison APentax K-r vs. K-x ISO comparison BPentax K-r vs. K-x ISO comparison CPentax K-r Measurebation - a set on Flickrvia Information on Digital Cameras (Japanese) and the brief post of the original tester at the DPR.And the remarks by the author is quoted:-"All photos were taken in DNG RAW and process with no additional noise reduction
