Just get a longer lens and it'll be more even. I have a Fujian 50mm F1.4 and it's pretty solid.JkTsang as you said the Fujian covers the M4/3 format but if you notice the sharpness is gone on the sides, the aperture 1.7 is great , the size is great. I find them more like special effect lenses than actual proper day today use, if you are happy with the limitations obviously at this price you will never find any other lens with such an aperture. Other thing the aperture is not constant throughout the frame , simply because it covers the M4/3 format does not mean it has the same light intensity in the center and the on the sides.
Is the fotodiox good. I have the $10 cheapies and they don't allow for infinity focus even though they say they will. It's the powder coating. I have to adjust each lens by a smudge to get it to infinity focus.I had a couple lenses from the 1940's (from my grandfather), so I spent the $20 on a fotodiox adapter.
Every Fotodiox adapter I have bought seems to focus past infinity, which I prefer over no infinity at all. It's only a small inconvenience to turn on the live zoom on my e-pl1 to dial it back to good inf. focus. The great thing about that is once you get there, you don't have to worry about the focus ring moving (the lenses I have require a deliberate amount of force to rotate).Is the fotodiox good. I have the $10 cheapies and they don't allow for infinity focus even though they say they will. It's the powder coating. I have to adjust each lens by a smudge to get it to infinity focus.
NVM. It is one the cheapies that don't allow for infinity focus as per the review.
Amazon.com: Fotodiox Lens Mount Adapter - C-Mount Movie Lens to Canon EOS Camera Adapter, fits Canon 1d,1ds, Mark II, III, IV 5D, 5D Mark II, 7D, 10D, 20D, 30D, 40D, 50D, 60D, Rebel xt, xti, xs, xsi, t1i, t2i, 300D, 350D, 400D, 450D, 500D, 550D, 1000