Olympus' M.Zuiko 75mm f1.8 is a lovely, well-constructed and -performing telephoto lens for photographing people. It's so nice, in fact, that I found myself wishing Olympus made lenses for larger-sensored ILCs.
The first two things you notice about the lens are the all-metal construction and that it's heavy; all that glass reminds me of Olympus' better Four Thirds-mount lenses. I tested it with both the Pen E-P3 and OM-D E-M5, and actually found it a little too heavy for the E-P3. Without the larger grip attached to the camera, I found that when I wasn't actively shooting, it weighed my hand down in such a way that I had to exert extra thumb pressure to grip it, which accidentally changed camera settings.
Manual focus has that typical servo-electronic feel, loose and endless, albeit reasonably precise once you're in the vicinity of the correct focus range. Autofocus performs normally on the cameras, neither slower nor faster than the cameras typically deliver (that includes on a MSC technology.I quickly tried it with). And the AF operates silently during video capture, as you'd expect from Olympus' use of its
The lens' sweet spot seems to be between f2.8 and f11. Below f2.8 it shows a slight propensity for chromatic aberration and it doesn't attain optimum sharpness until there -- though it's still quite acceptable -- and sharpness declines a bit between f8 and f11. I was very disappointed with f22, however, which I found simply too soft to use. This pattern applies to both center and corner sharpness, as it's pretty consistent edge-to-edge.