I was reading Amin's comments on the Sony RX100, which got me re-reading dpreview's comments on testing it, which reminded me of a comment I read about how some camera labs re-focus on the corners when determining resolution to account for field curvature (this last statement may be apocryphal, but that's how I remember it). Still, I don't get it. Without getting all technical and all that, isn't field curvature just a reason why some lenses aren't very sharp away from the center? Does it really matter what the origin of the softness is? In other words, if the RX100 has a lot of field curvature at short focus distances, isn't that the same thing as saying the corners will be very soft at close focus distances? And, if so, why don't the reviews just come out and say it? Sometimes I get the impression that some people exempt field curvature from the list of lens flaws. A lens might be described as very sharp, but suffer from a lot of field curvature. Isn't that an oxymoron? I apologize if I'm just broadcasting my ignorance about optics in general.