Originally posted by normhead Ok, now there's a difference, using the K-3 at 6400 there is enough noise to produce sharpening artifacts.
Not only are you comparing with different noise reduction applied (in-camera), you also show the K-3 image at higher magnification.
You appear to have cropped out the same sized pixel area for both cameras, which shows pixels at the same size, whereas the K-3 pixels should be smaller by a factor of 2/3 to provide a fair comparison.
There is no question that a smaller pixel (from the K-3) will look worse than a larger pixel (from the K-5) when both are shown at the same size. The question is whether the K-3's larger amount of pixels can compensate the higher per-pixel-noise, accordingly.
Originally posted by normhead Both cameras are set to Auto high ISO noise reduction... maybe i should I've it a try with NR turned off.
Yes, please turn of all in-camera noise reduction.
Please also leave the EXIF data intact. In one comparison you show two crops, one from the K-5 and one from the K-3, but there is no difference in magnification this time. How did you scale down the K-3 image? If you leave the EXIF data intact, we can make sure that no errors happen (things like that happen, as your first post demonstrates).
Making fair comparisons isn't as easy as it sounds. The results from Tjompen1968 look like what I'd expect and are in line with what DxOMark results.