Originally posted by Ash You're right Andi, and I haven't posted 100% crops - a little lazy at the moment, or maybe just exhausted...
I'm just keen to know, from anyone who may know, under what conditions would such a lens produce a hazy image when used wide open?
While I don't own this lens, and I also am unable to view the photos you linked to, I can offer some general comments and ideas which may help.
Firstly, a slight misfocus can often result in a "hazy" appearance. Have you checked to see if this lens is BF/FF with your body? Also, it could well be that the AF unit is simply not precise enough for the thin DOF at 200mm and f2.8. I have found that AF is often an "approximation", and to be absolutely certain I switch to MF. However, as you know it's hard to MF with the stock screen, but this is where LiveView (magnified view) can help, even with the blocky pixels (hint: look for contrast changes).
Also, what you're observing could be due to lens flare. In a long zoom such as this with close to 20 elements, there is a greater chance that flare/reflections will take their toll. You could try using a more "aggressive" lens hood.
Finally, what are you comparing these to? In this age of digital it's so easy for us to make comparisons - perhaps we are simply expecting too much of these long zooms?