Ctein, By your reply I take that you have been shooting Jpeg only with the 12mm? It doesn't make such difference though. If you check the LensTip review you'll see that before (in camera) correction the lens has a huge amount of barrel distortion. That is probably unavoidable if one wants to build a lens that is both small and super wide. Now I know from experience that when one corrects a Fisheye in PS to make it linear, one has to throw away part of the image because of 'stressed pixels' at the edges. This smearing happens too to the m.4/3 9-18, so I take that it is unavoidable in m4/3. This lens however is fast. When introducing it Olympus presented it as a street shooter, not as a landscape lens. So you might reconsider the intention. In mirrorless, with short distance to flange, one can't have everything. Or else, as said above, one should use older 4/3 telecentric lenses for landscape, as I do with the old 9-18: no smearing at the edges. But the lens with adapter is way bigger. You won't have this problem with teles, only with lenses whose focal is shorter than the m4/3 register, some 20mm.

I had noticed some smearing in the corners in early sample images. I have a 4/3 9-18 for comparison., which is sharp from edge to edge. However the m4/3 9.18 has the same problems, so my impression is that digital correction has problems with superwides and does some 'pixel stressing' at the edges, when correcting. In other words it might be a format/distance to flange problem with wides in mirrorless, where APS is even worse (see NEX 16 mm).