Corner sharpness on the wide end when focused in the center of the frame is very good, even when shooting wide open, and results sharpen up only very slightly when focusing in the corner, indicating minimal field curvature. The lens is so sharp wide open in the center that stopping down to F6.3 only reduces sharpness slightly, due to diffraction (remembering that F6.3 on Four Thirds is F12.6 in full-frame equivalent terms). The Sigma 56mm f/1.4 DC DN is part of a range of compact prime lenses designed for APS-C and Micro Four Thirds mirrorless cameras. With a bright f/1.4 aperture, this is a great portrait lens, giving a 112mm equivalent on Micro Four Thirds cameras. It’s also relatively compact, and would make a great choice for anyone needing to shoot in low-light conditions, or for portrait photography. As part of the Pro range, the 25mm f/1.2 is built to its highest standard of quality. The all-metal barrel construction exudes quality and precision, and feels like it should easily withstand some not-so-gentle treatment. It’s designed to be dust-proof, splash-proof and freeze-proof, and I shot with it during a heavy autumnal shower with no ill effect.

The 12-60mm lens gives a useful zoom range from 24-120mm equivalent, with optical image stabilisation, and a more affordable price tag compared to some lenses. Focus is snappy, and image quality is respectable, making it a great upgrade option for those with a 14-42mm kit lens. The lens is weather resistant (against dust, rain, and frost). It also features a L-FN button and Olympus manual focus clutch, which provides real manual focus with a depth of field scale and hard stops. The latter is extremely useful for shooting video and close-up images. As we noted in our review, it’s also not as sharp as other lenses, particularly at the telephoto end of the lens. This is often the case with super zoom lenses. We found it highly enjoyable to use, even if it did struggle noticeably in low light. ProsThis is something of a niche lens – do many shooters need a weather-sealed fisheye? Not many.But if this is your niche, you’re in for a treat. Pros If there is one area one might criticize the Olympus M.ZUIKO 25mm 1:1.2 PRO it is its behavior against bright light. If the sun is in the frame flares are very likely. Here is an extreme example: Above: Moving into the far corner, there’s a minor drop in sharpness, but still respectable quality at the maximum aperture. Closing the aperture gradually to f11 didn’t make any significant difference in this particular test, so the Olympus was performing at its best pretty much out of the gate. I also retested with the focusing area repositioned from the centre to the corner and the results were the same. For a lens of its focal range and build, the Olympus 8-25mm F4.0 is very compact and lightweight. Its small size has been achieved thanks to a first for an Olympus Pro-branded lens: a retracting zoom design. Nor are there really any good alternatives available to Micro Four Thirds shooters in this focal range. The closest option, Panasonic's Leica 10-25mm F1.7, is of course much brighter and offers better depth-of-field control, but it's also a far less portable and much more expensive.

This lens arrived at our review desk at a similar time to the 21mm f/1.4 ED AS UMC CS, and we were sceptical as to whether it could deliver the same kind of ultra-impressive image quality. We needn’t have feared – the Samyang 50mm f/1.2 UMC CS is absolutely sublime, producing stunning results at its shallowest depth of field with that f/1.2 aperture. For MFT portrait shooters, it’s an ideal choice, as long as you don’t mind putting in the work of manually focusing. Pros You work out a lens’ full-frame equivalent focal length by multiplying th The OM System M.Zuiko Digital ED 100-400mm f/5-6.3 IS lens is a mid-range telephoto zoom that gives a 200-800mm equivalent, although with a relatively slow aperture, you do need bright sunny conditions to get the best out of the lens and camera. It’s also compatible with the Olympus MC-14 (1.4x) and MC-20 (2.0x) teleconverters if you want even more reach. We put this lens in the hands of professional photographer Andrew Fusek Peters for a full field test, and he came away very impressed indeed. Sharpness remained consistently good throughout the zoom range, and when light levels were just so, the images the lens produced were nothing short of sublime. Pros

Defy the moment

At that minimum distance and with the lens at its telephoto position, you'll manage a maximum magnification of around 0.21x (35mm-equivalent: 0.42x), while at the wide-angle position this falls to about 0.07x (35mm-equivalent: 0.14x). Above: Moving into the corners shows the lens becoming a little soft compared to the middle, but close it to f5.6 and it sharpens up nicely and there’s no benefit to closing any further at least in terms of detail.