This is the latest addition to the Olympus range of premium prime lenses for the micro Four Thirds system cameras. It can be used on either Olympus or Panasonic cameras. The new lens is not to be confused with an older 17-millimetre f2.8 unit. The new optic is faster, sharper and has quicker autofocus. Switching between auto and manual focus can be done in-camera - in which case you get the focus-assist enlargement of the LCD image - or by sliding a clutch ring on the barrel. That way there is no enlargement of the LCD image but the smooth focus ring has stops at each end of the focus range, which is preferable to having the ring go around endlessly, as it does when the in-camera manual focus is selected.
Optically and mechanically this lens is outstanding. There is very slight barrel distortion, which is to be expected in a 34-millimetre equivalent medium-wide angle. From f5.6 we were satisfied with the overall sharpness of the image. The compact dimensions and its lightness, combined with the superior construction materials, make this an ideal walk-around lens.
It is a shame to have to trade off the lovely action you get when the manual focus is selected on the lens with the loss of the manual focus assist.
For anyone who has owned and loved an Olympus OM camera, this lens (and its companions in the M.Zuiko premium range) is a return to the good old days of brilliant, beautifully made prime lenses. And now we have the added benefit of lightning-fast autofocus. What more could we ask for?