1. Introduction 2. Design and Operation 3. Test results 4. Conclusion & samples

Design

The 9-18mm bears a strong family resemblance to Olympus's familiar 14-42mm kit zoom; it's near-identical in styling, fit and finish. With most other manufacturers this could be considered a damning indictment, but in this case it's no bad thing at all, as the 14-42mm is one of the better-made of the budget kit lenses. Accordingly the the exterior is made from lightweight but high quality plastics, and the 9-18mm gains the welcome addition of a metal lens mount. The broad zoom ring occupies most of the barrel, with the focus ring at the front. However unlike Olympus's 'Pro' and 'Top Pro' lenses (e.g. the ZD 11-22mm F2.8-3.5 ED or the ZD 7-14mm F4 ED), this one isn't sealed against dust or moisture.

'Focus-by-wire' manual focus

The most unusual feature of this lens's operation is the focus-by-wire manual focus system, which drives the focusing group indirectly via the lens's autofocus motor (as opposed to the direct mechanical connection found in most lenses, including Olympus's most recent SWD models). As a consequence, the feel of the manual focus ring never changes, regardless of whether the camera is set to auto or manual focus, or the focus has reached the limits of its travel (either close or infinity), and this lack of tactile feedback can be a little disconcerting in some situations. However, this system does have some advantages; it allows gearing of the focus action, such that turning the manual focus ring quickly makes very fast initial adjustments, but then turning it slowly allows very fine subsequent tweaking. This essentially mimics the effect of having an extremely long focus travel, and consequently (in principle at least) allows a high level of manual focus accuracy, especially when using live view.

On the camera

The lens is remarkably compact and lightweight for an ultra-wideangle zoom, due in part to the rather modest maximum aperture, but also realising the downsizing benefits of the small Four Thirds sensor format. At a mere 280g you'll hardly notice it's on the camera, and for this reason it matches particularly well with Olympus's small lightweight E-4x0 and E-5x0 series bodies. However it's also quite at home on larger bodies such as the E-30. The zoom ring fall naturally to hand and the focus ring perfectly accessible when you need it. With no signficant change in length on zooming, the lens remains well-balanced at all focal lengths.

It's worth pointing out that this lens isn't terribly compatible with the on-board flashes found on DSLRs; most of these only cover an angle of view equivalent to using an 14mm lens. At wider angles, the flash will give uneven frame coverage with darkening towards the corners, coupled with shadowing from the lens itself in the lower centre of the frame. This is absolutely normal for a wideangle zoom; if you really want to use this lens with flash you'll need to invest in a suitable external unit.

Autofocus

The 9-18mm feature's Olympus's traditional micro-motor focusing system, again very similar to the 14-42mm kit lens. This isn't particularly fast, but it's certainly fast enough, as typical subjects for ultrawide lenses (e.g. landscapes and interiors) are perfectly willing to wait. The immense depth of field inherent to such short focal lengths will also cover up any minor focus errors which do occur, so on the whole there's little to complain about here.

The lens is specifically designed to be compatible with contrast-detect autofocus in Live View on compatible Four Thirds camera, and works very well in this mode. Indeed it was unusually fast and reponsive on all of the cameras we tested it on, including the Olympus E-30 and Panasonic DMC-L10. The 9-18mm is also fully compatible with the contrast detect AF of the Micro Four Thirds Panasonic G1.

Lens body elements

	The lens features the 'open standard' Four Thirds mount, currently compatible with DSLRs from Olympus and Panasonic. Communication with the camera is all-electronic, via the gold-plated contacts. The lens features some rather minimalist moulded grips on the side of the barrel to aid mounting/dismounting; they're not great, but better than nothing.
	The filter thread is 72mm, and does not rotate on autofocusing, which is helpful when using polarisers or neutral density gradients (the most likely to be found in front of this lens). The good news is that standard-mount (8mm thick) polarisers may be used without vignetting, so you won't necessarily have to pay extra for slimline versions.
	The petal-type LH-75C bayonet-mount hood is provided as standard, and fits positively onto the front of the lens. It's made of black plastic and features ribbed mouldings on the inside, to minimize reflections of stray light into the lens. White arrows on the outside aid alignment for mounting. The hood is however 94mm (3.7") in diameter, so takes up a fairly sizeable slot in your bag.
	The rubber grip on the zoom ring is 22mm wide, and the action is smooth and precise. It rotates 80 degrees clockwise from the 9mm to 18mm positions. The lens is physically shortest midway between the 11mm and 14mm settings, and the front element extends a mere 3mm on zooming to either 9 or 18mm.
	The focus ring is 10mm wide, and while its action is perfectly smooth, it gives no tactile feedback on operation at all due to the 'focus-by-wire' design.

Reported aperture vs focal length

Here we show the maximum and minimum apertures reported by the camera at the marked focal lengths.

1. Introduction 2. Design and Operation 3. Test results 4. Conclusion & samples