Olympus M.Zuiko Digital ED 75mm F1.8 Preview
2 Design and operation
The 75mm F1.8 is an exquisitely-crafted lens, with a barrel and focus ring made from metal in a similar fashion to the company's 12mm F2 wide-angle prime. Sadly it doesn't share that lens's clever focus-by-wire manual focus that combines linear 'gearing,' heavier damping and solid end stops to make it feel like a physically geared system (without question the best manual focus implementation we've encountered on a focus-by-wire lens). Instead the 75mm uses a conventional focus-by-wire system that is sensitive to the speed at which you turn it. Focusing is internal, so the filter thread doesn't rotate, and like other recent Olympus lenses is fast and near-silent, so it shouldn't intrude on movie recording.
Like many of Olympus' recent lenses, the 75mm is only available in a silver finish, which many users find a poor aesthetic match to black camera bodies. We're inclined to the opinion that if the lens offers excellent results, then this should be a minor concern, and refusing to buy one simply because it's silver isn't a terribly rational response. All the same it would be nice to see Olympus offer the 75mm in black (along with the 12mm F2 and 45mm F1.8, hint, hint).
On the camera
The 75mm F1.8 is almost precisely the same size as the Panasonic 12-35mm F2.8 zoom, launched just days earlier. The result is a lens that looks the part without being disproportionately large on either a DSLR or rangefinder-style body. It's the same weight as the zoom, too, meaning it results in fairly hefty combinations, but ones that don't tip over into 'too heavy' territory.
Lens body elements
Although the lens we've currently got is pre-production, it's close enough to being finished for us to form some early impressions but it's worth remembering that there could be some changes in the finalized product. The build quality is impressive - it's a very solid-feeling lens with a very smooth motion to the focusing ring. On this example the focus ring is very lightly damped, which means it can move slightly more freely that its looks suggest.
Autofocus is fast and, though doesn't quite have the near-instant feel of its 45mm sibling, any difference is only really noticeable when making large changes in focus distance (for example close-focus out to infinity). Making smaller adjustments is extremely fast. Focus is effectively silent - you have to press your ear to the lens to know anything's happening.
Most of all, though, the early shots we took with the lens have showed really impressive levels of sharpness at the point of focus. There's a pleasant transition to out-of-focus regions and smooth bokeh with only a hint of the axial chromatic aberration you'd expect on a lens like this. We haven't been shooting brick walls, so won't comment on corner-to-corner performance, but we've seen enough to leave us keenly anticipating the production lens we've been promised. We'll start to prepare a gallery of samples as soon as it arrives.