A LITTLE GOES A LONG WAY

decided to build its own model (although we suspect the Lumix lens has ended up on quite a few OM-D bodies). Back in 2016 Olympus was promoting its 300mm f/4.0 prime telephoto, which was equally as brilliant, especially when you weigh up – literally – the size and price of any 600mm f/4.0. But it’s a bit of a specialist lens, while the 100400mm is much more versatile, especially given its size, translating into excellent portability and very easy handling. Incidentally, it takes over from the 300mm f/4.0 as the longest lens in the current M.Zuiko Digital lens system. The Olympus M.Zuiko Digital ED 100-400mm f/5.0-6.3 IS is fractionally slower than the Panasonic lens at 100mm

As the chief protagonist for the Micro Four Thirds mirrorless camera format, Olympus is again making the most of what can be achieved with telephoto lenses, this time with its own version of the very versatile 100-400mm telezoom.

(f/4.0-6.3), but is pretty similar in all its other aspects, making it an equally attractive proposition for subjects such as wildlife, sports, action and travel photography, as well as more general usage.

HOLDING STEADY

Dimensionally, it’s much the same size and weight as a typical fullframe 70-200mm f/2.8 zoom – the length is just over 205mm and it tips the scales at 1.325kg with the tripod mounting collar attached. This can, of course, be detached if you want to travel even lighter (by 205g) and, in practice, you can easily contemplate going this way because hand-holding is realistic in many shooting situations.

Optical stabilisation delivers up to three stops of correction for camera shake at the 400mm focal length, with adjustments for yaw and pitch. However, the lens isn’t compatible with Olympus’ Sync

IS, which combines forces with the OM-D in-body stabilisation and is available with the 300mm f/4.0 and the 12-100mm f/4.0 (the only two other M.Zuiko Digital lenses with optical stabilisation), but IBIS does add roll correction. However, it appears the communication between the two systems isn’t as advanced to allow five-axis stabilisation and, thus, the full scope of correction available in a camera body like the E-M1 III or E-M1X. Nevertheless, it’s still enough to give some leeway if you can shoot with slower shutter speeds and prefer this route to more exposure rather than pushing up the ISO setting. Using the 1/focal length equation for the minimum ‘safe’ hand-holding shutter speed, three stops of correction gets you to 1/100 second when shooting at the effective 800mm.

Mind you, with the largest aperture being f/5.0 at 100mm and f/6.3 at 400mm, you’re going to be chasing all the ways of achieving image brightness that are available and, if you also happen to need faster shutter speeds (to freeze movement), then increasing the sensitivity is likely to be your one and only option.

UP CLOSE

Externally, the Olympus 100400mm’s construction uses a mixture of GRP and metal barrel tubes with full sealing against the intrusion of dust or moisture. In fact, Olympus says the weather protection is to the same level as that of its PRO series lenses. The lens certainly looks and feels very solidly built, again to the same level as the PRO models.

Zooming is via a ‘trombone’ mechanism, but even fully extended at 400mm, this lens still isn’t particularly long. The focusing ring is ahead of the zooming collar and is an electronic fly-by-wire control. Switching between AF and MF is done conventionally via a switch on the lens barrel rather than push/pull clutch mechanism that Olympus employs on quite a few of its other lenses. The other controls on the lens barrel are a zoom lock (which engages at 100mm), the IS on/off switch and a zooming range selector that has settings for 1.3m to 6.0m, 1.3m to infinity and 6.0m to infinity.

Obviously 1.3m is the zoom’s minimum focusing distance and is maintained across the focal range, meaning that, at 400mm, it gives a useful maximum reproduction ratio of 1:1.75. This is just a little bigger than half lifesize, which means this lens is great for smaller subjects such as birds or even some insects like butterflies.

Quite often, the major limitation with supertelephoto lenses is their longer minimum focusing distance that results in a very small reproduction ratio. The 100-400mm is an MSC lens – it supports Olympus’ Movie & Still Compatible autofocusing control for smoother and near-silent operation in the continuous mode. The lens also supports the focus stacking function available on the E-M1X, E-M1 II/III and E-M5 III.

On the inside, the optical construction comprises 21 elements in 15 groups and a total of eight are special types. A quartet of elements made from extra-low dispersion (ED) glass are there to minimise chromatic aberrations, while the other four have high refractive index (HR)