Originally posted by bossa 
Sharpness is not resolution.
Sharpness is generally considered to be acutance, which is related to perception and the resolving power of the human eye and the way the brain interprets visual information. The K-5IIs may well have more perceived sharpness (acutance) in certain situations than the K-3, taking contrast, noise and cropping into account, but the K-3 would always have superior resolving power with the same lens attached. At the pixel level the K-5 has less noise than the K-3 and so the advantages (of k-3) may only be apparent at low iso's when extreme cropping is needed. All the same the ability to crop is almost as good as being able to afford a super telephoto:
From my experience the K5 familly (K5, K5-II, K30, K50) all apply lot of blur to the image
on the RAW (yes you read it correctly) starting 1600iso, and even more after. When doing comparison on RAWs developpement with DxO (and having the automatic noise removal algorithms), the K3 high iso are much sharper with much more details than what you get from K5 familly. Because of the blurring algorithm the different is much more visible than 16 vs 24MP... It is more like 6-8MP vs 24MP.
This is what DxO tests confirm when testing the K5 body. When K5 was just out, few would have access to a noise removal software of enough quality. Pentax has just decided to add some blur and it worked well, everybody raving about the high iso quality. Other members of the K5 familly just inherited the same algorithms.
You can typically check that on a controlled environment by getting the Raws of DPreview and develop them in lastest DxO (or lightroom) with proper noise removal settings. You can get many raw of different camera from the same scene in studio. You might find that K3 shoots are just sligly more noisy by cropping to 100%, but you also notice that there is much more detail and information visible on the K3 shoot than on K5 shoot.
I'am afraid K5-IIs has the same problem as K5 exactly as being part of same familly and having the same processing CPU onboard.
This show only when working withs RAWs. When working with Jpegs, K5 high isos shoots are better than K3 high isos shoots, because both use Pentax noise removal algorithm that is far from being as good as what DxO does for example. Working with Raws and proper noise removal software, the K3 high isos shoot retain much more detail than K5 shoots.
Post #15 by bossa
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