10-07-2013, 11:36 AM
Quote:What does this exactly mean? Can diffraction be cancelled by lens design? How is it possible?
No it can't (as far as I know of). I'll try to rephrase my statement:
Before the release of the 12-40/2.8 all Olympus mft standard zooms had a maximum aperture of f/5.6 (or f/6.3) at the long end, which is equivalent to ~f/11 on full frame. At this point diffraction effects already start to kick in. Look at the test results for the 14-42R, for example, and you will notice that stopping down actually reduces the resolution of the image.
In contrast, stopping down the 12-40/2.8 by one or two stops should yield a better lens performance (as usual when stopping down a lens), because you're not instantly diffraction-limited.
So, in the end, I expect the 12-40/2.8 to be the best performing mft zoom (produced by Olympus) at 40mm f/5.6.
I hope that was somehow more clear now... :ph34r: