Originally posted by pcarfan I agree. My Tamron 17-50/2.8 is very sharp for close objects not good for distant ones. Some 85/1.4 portrait lenses do the same. In my experience, it's rare for a lens not to be sharp at distance and less sharp for close subjects. This is why I think sharpness figures on reviews doesn't tell the whole story even about sharpness alone. Then you throw in micro contrast and at times it becomes very murky.
This is the thing that prompted this particular line of thought on my part. I just put my new Pentax 55-300mm lens through some initial field tests (aka Snapshots
), and I found that I get remarkably good (relatively speaking) photos at the low FL and short distances, and much lower IQ at larger (but not necessarily great) distances and longer FL. Sure, this is just a modest lens, but the IQ at short FL and small distances is so surprisingly good, that it made me start to wonder if the relatively poor showing at the longer FL/distances is just a lens limitation, or if there are some other contributing factors.
BTW, if I read you correctly (and I'm not sure I do), your statement "it's rare for a lens..." is the opposite of what your first sentence says. Am I misunderstanding something?