Olympus Zuiko Digital ED 50mm 1:2.0 Macro £755
21st Oct 2011 | 15:44
A dust and splash-proof macro lens
Overview and features
One of a handful of macro lens options for Micro Four Thirds (MFT) users, the Olympus Zuiko Digital ED 50mm 1:2.0 Macro provides an effective focal length of 100mm when used with Four Thirds cameras, but with an actual focal length of 50mm it's much smaller and lighter than other 100mm macro options.
It contains 11 lenses arranged over 10 groups - among them, a single Extra Low Dispersion element. This is in place to help minimise chromatic aberration. Olympus has also incorporated a floating focusing system that corrects for aberrations throughout the optic's focusing range.
While the lens only offers a 0.52x magnification (half life-size) as standard, Olympus claims that the crop factor applied by Micro Four Thirds bodies results in images that more closely resemble those shot with 'true' macro lenses, which offer 1:1 reproduction ratios.
Should this not be enough, the lens can be combined with the EX-25 extension tube, which doubles its magnification.
The Olympus Zuiko Digital ED 50mm 1:2.0 Macro lens is small and only marginally heavier than non-macro 50mm lenses, and it's finished to match Olympus DSLR bodies. It's also one of the few macro lenses to be sealed against dust and splashes of water, and so it's a good match for the Olympus E-3 and E-5 DSLRs that offer similar protection against adverse conditions.
At its rear there's a solid metal mount, and above it sits a small but clear distance window, which displays distance in both feet and metres. Unlike similar lenses, however, there's no indication as to the lens' current reproduction ratio, while on some bodies such as the Olympus E-5, it's difficult to see the distance window clearly thanks to the overhang of the fill-in flash.
Neither a focus limiter nor an AF/MF switch feature on the barrel, so focus modes need to be changed through the host body. Externally, the only other features are a rubber focusing ring and a 52mm filter thread, as well as a bright red index dot to aid mounting.
The optic's size adds little to the overall profile of a Micro Four Thirds DSLR, and although its focusing ring is a little shallow, it's hard to imagine it realistically being any larger on such a small lens.
Performance and verdict
The focus ring turns freely and is easily accessible by the user's thumb or finger, or combination of the two. But because it moves the lens group electronically rather than mechanically, it can't be used to fine-tune autofocus as with similar macro lenses.
This lens is fairly slow to focus manually, which for a macro lens is undoubtedly preferable to a system where it's far too fast be controlled precisely.
The lack of an internal focusing system means that the lens extends to almost double its length when used at its closest focusing distance.
The lens takes a step-by-step approach to autofocusing, first getting the general area right before taking a little longer to find the exact position. Autofocusing speed is perfectly respectable, although it's a shame that there's no Supersonic Wave Drive motor as it falls a little behind lenses with similar technology in place.
This also means that it isn't as quiet either, joining the Pentax smc D-FA 100mm f/2.8 macro WR and Sony 100mm f/2.8 Macro lenses in the noisy corner.
Wide open, the Olympus Zuiko Digital ED 50mm 1:2.0 Macro turns in some weak results in terms of sharpness, although in this respect it's hardly alone among macro lenses.
Things are much better once the aperture is stopped down, though, and it does a good overall job to match the performance of rival lenses up until its maximum aperture of f/22. While lab testing shows it to have relatively poor control over distortion, it does far better at keeping chromatic aberrations to a minimum.
It's worth noting that thanks to the relatively small sensors with which this optic is used, it's far easier to obtain greater depth of field in images. This is of particular relevance to macro photography, because depth of field at close focusing distances is incredibly narrow, which can be problematic if the focus falls slightly outside of what is expected.
Overall, the Olympus Zuiko Digital ED 50mm 1:2.0 Macro is a good performer, but one with room for improvement. At this price many would no doubt trade its weatherproofing for a more refined focusing motor. Nevertheless, once it's stopped down towards its middle apertures, its sharpness equals that of similar lenses, and its control over chromatic aberrations is just as admirable.