Correct me if I'm wrong, but aren't some of the things they're complaining about (vignetting and edge softness) likely to be better corrected on a Panasonic body than on the Olympus they used?
The key line for vignetting is this one:
'It should be mentioned here that if you save photos in JPEG format, the vignetting values are by several percent lower – it is due to aforementioned cropping of images after correcting the distortion.'
They forgot to add, though, that this comment applies equally to raw files which are converted using a program that supports the cameras correctly - i.e. the ones suppled with the cameras, or any of the major third-party converters (in fact you have to go out of your way to find one that doesn't apply corrections).
What they're complaining about seems to be that the extreme corners, which are designed to be cropped out of the final image after distortion correction, aren't fully illuminated. They're only seeing this by insisting on using dcraw and not applying the corrections that the vast majority of users will be using automatically, regardless of which brand body they use (Panasonic and Olympus necessarily apply distortion correction in the same way).
As for edge sharpness, to an extent this depends on where they are taking the measurement from. But the shots I've taken with the lens so far (including those in our GH2 14/2.5 preview samples gallery) suggest that it is genuinely a bit weaker towards the edges. Note software correction doesn't ever improve this.
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Andy Westlake
dpreview.com
