This is basically a question to Andy. As I already wrote in the outdoor thread I have a problem with pictures taken while in Croatia - in general far objects are never sharp. Initially I thought it is a problem with one of the lenses I was using, but after some browsing I realized it is not just this one lens, but the same happens with all lenses used (and - together with Marzena - we have a nice collection now ). So there are two possibilities. One - it is a body and autofocus problem. This one I can test here, and I will do it - it is just a matter of time and weather. However, I wonder... is it possible that the problem was related to the place? What I mean is - temperature was high for the most time, I don't think it was ever below 30 deg C when I was taking pictures. Could it mean air motion, density waves, refraction, aerosols - whatever - that makes taking sharp pictures from the distance simply impossible? I know it is a problem in astrophotography, I wonder if it can't work the same way in normal photography. As the light was very bright, many pictures were taken with very fast shutter speed, so in theory it shouldn't be a problem? Distant objects are always a little bit blurred in Croatia (well, distant objects means in this case 10 to 20 km), that's most likely some natural air pollution - can it be the problem? This particular picture is probably not the best example, as EXIF info about distance is rather strange (0.64? no idea what it means), but that's how the situation looks on most pictures (this is yet another lens, wider). First, general view: And 1:1 crop: Second plan is way too soft, while the tree trunk looks much sharper (or it doesn't? I am am stopping to believe my eyes). At 12 mm focal length and 8 Av DOF should extend behind known Universe, and not end just a few hundred meters from me, shouldn't it?