Originally posted by racingsnake i am using a k-5 IIs. no lenses i have ever used with it needed any af adjustment. the thing shoots great as is.
Which does not mean at all that your DA21 has a problem. The fact that the manufacturing tolerances of your body and lens are not perfectly matched does not imply a problem with either.
Originally posted by striker_ The DA 21 is not one of the sharpest lenses but acceptable sharp
I disagree with that comment. The DA21 is a really sharp lens. It might not be AS SHARP as other limiteds but it is sharper than most non DA* or limited lenses. It also has great contrast and saturation results, which increase the feeling of sharpness.
Regarding the original question, I cannot open the DNG files at work, but looking at the images you posted afterwards, they look fine to me. The colours are superb, they seem sharp (the tree might be oversharpened?). The lack of an AA filter might play a role indeed, with my K20D I've never had any issue with that lens, it's one of my favourite, a lens with personality!