Morning,
No I don't judge sharpness solely by a lens aperture, at least I don't now. I give points more on quality of the lens as in EF-S, EF, and L's. I know the aperture is only a measure of light a lens can process, which in turn I think can effect sharpness in certain situations. But I could be wrong here. Far as reviews I agree with you. I noticed from the beginning when I started reading them, the reviews are all over the board for most lens. That has always been a big puzzle to me....how can the same lens be seen as good by some and so very bad by so many others. I'm beginning to believe it has more to do with the experience and knowledge of the user....how much they know, understand testing lens persay, and how they use a lens. What is the yardstick they're judging a particular lens by. Most don't have yours, Bob's, or other qualified guys, knowledge and experience, with a wide range and quality of lenses. I have also considered that quality control at the manufactuer end could be a part of it. Some lenses may not completely meet the specs through a whole manufacturer assembly run. It may pass inspection of the tolerances the inspector measured for, but may still be a little off in some way from some of the others in the run, I dunno. I would love to personally test a lens myself before I buy, but I know no way to do that in a practical way. I can only conclude that lens manufacturing is not yet a perfect process, as far as the physical production part of it. That may be 1 reason for so many different findings from so many user's.
One thing I notice (with myself) is that on the surface of checking out a lens it's not quite so obvious to tell the quality of the sharpness of one lens from some to others. Case in point, when I 1st got my EF 25-105mm L. the difference between it's sharpness and quality, and my EF-S 18-200mm, seemed a little better (the 24-105mm), but not so great. But I was comparing pics from different ranges...not at the same range. The pics were not of the very same scene, or same lighting. Only after close inspection of my pics of simular scenes and lighting did I begin to see more a difference. I began to notice better color saturation and sharpness with the 24-105mm. More detail and clarity. Then I began to notice the quality of the lens, and the smoothness of it's controls and movement, better auto focus, etc. I began noticing the better detail in it's build. Gradaully I saw the overall better quality and sharpness of my 24-105mm over a day or so. But, I had diect comparison between it and my 18-200mm, I had both in my hand, for A-B comparison. Point I'm making is, I took time and care for a acurite comparison. I have'nt read very many user reviews where they took care of a fair test of the lens.
I tended to give more credence to a reviewer that says most of his lens are L's and he does Pro to simi pro work,or serious photography, than a average joe whose stepping up from a kit lens with not much photo experience. But I don't take those revews anymore for the gosple. I'm at the point to just test myself. I may have to buy, test, and send it back if I don't like it.
