OM System M.Zuiko ED 100-400mm F5.0-6.3 IS II Lens

Olympus 100-400 Overview

The OM System M.Zuiko ED 100-400mm F5.0-6.3 IS II Lens gives Micro Four Thirds photographers a 100-400mm zoom with the angle of view associated with 200-800mm on a full-frame camera. Its range suits birds, mammals, outdoor sport and subjects that resist a close approach. The 100mm end helps acquire a moving animal or frame a larger subject; the 400mm end narrows the field around a distant bird without a change of lens. Optical stabilisation, compatibility with five-axis Sync IS on supported OM System bodies, weather protection and a detachable tripod mount support the demands of long days outdoors.

This second-generation lens matters for reasons beyond the focal length printed on the barrel. The earlier 100-400mm already reached 800mm in full-frame-equivalent framing, but lacked coordinated five-axis Sync IS. The IS II adds body-and-lens correction, a fluorine coating on the front element and a revised tripod mount. It retains the familiar 100-400mm range, f/5.0-6.3 variable aperture and 1.3m minimum focusing distance. Those changes matter most during handheld observation, careful framing at 400mm and repeated work in damp or dusty places.

The lens balances long reach against a modest maximum aperture. At 400mm, f/6.3 calls for attention to shutter speed and available light when a bird moves quickly. Stabilisation steadies camera movement and the view through the finder; it cannot freeze wings, running animals or athletes. The strongest results depend on the subject, the paired camera, the distance and the shooting conditions, not on focal length alone.

Performance and Real World Capabilities

A Zoom Range Built Around Distance

The actual focal length runs from 100mm to 400mm. On Micro Four Thirds, the sensor records the angle of view associated with roughly 200mm to 800mm on full frame. That framing advantage places a heron on the far side of a pond, a bird high in a tree or an athlete across a pitch into a tighter composition without carrying an 800mm full-frame lens. The camera leaves the lens’s actual focal length unchanged. Sensor dimensions account for the narrower field.

The fourfold zoom range also changes handling at the moment a subject appears. Starting at 100mm makes a bird in flight easier to locate in the finder than an immediate attempt at 400mm. Once tracking feels secure, a turn of the zoom ring tightens the frame. For a larger animal approaching through woodland or a racing car moving closer along a circuit, zooming out protects the composition from an abrupt crop. A fixed long telephoto lacks that rapid change of scale, though a brighter prime has an advantage under poor light.

At the long end, a stable camera and responsive autofocus matter as much as the nominal 800mm-equivalent angle. Small movements send a narrow frame across the scene, and even good subject recognition sometimes loses a bird against dense branches. This lens supplies the field of view; the body supplies subject detection and recording speed.

Stabilisation on the IS II

The IS II supports coordinated five-axis Sync IS with compatible OM System cameras. Under OM System’s stated test conditions, the combination reaches up to seven stops of correction at 100mm and 5.5 stops at 400mm. The lens alone carries a 4.5-stop rating at both ends under a separate test. Quoting only the headline seven-stop figure for the entire zoom range conceals an important difference at the focal length most bird photographers use.

The stabilised view improves composition during handheld work. At 400mm, it becomes easier to hold the frame on a perched subject, study its position among branches and place the autofocus area accurately. Actual steadiness varies with body compatibility, stance, distance and camera movement, so a measured compensation rating never replaces a practical shutter-speed decision.

A stationary owl on a branch permits a slower shutter than a bird about to take flight. With the latter, faster exposure remains necessary regardless of stabilisation. Panning a moving subject introduces a different pattern of movement from holding a static scene. A monopod or tripod still makes sense during long waits, repeated compositions and photography under weak light, even with a stabilised lens.

Autofocus and the Focus-Limit Switch

The lens uses OM System’s MSC focusing mechanism and includes a three-position focus limiter. Restricting the active distance range stops the focusing system from travelling unnecessarily towards the close end when a distant subject briefly leaves the focus area. That becomes useful when following a bird among reeds or trying to regain a runner after another person crosses the frame. The wider focus range remains available when subjects appear at very different distances.

Camera settings have a substantial effect on the result. Bird and animal recognition, tracking behaviour and burst rate belong to the body, with the lens responding to focus instructions. A difficult background, low contrast, a teleconverter or fading light still slows acquisition. The lens carries no manual-focus clutch and no programmable L-Fn button, so its actual control layout sets handling expectations. Focus-limiter and stabilisation switches on the barrel address the most common lens-side adjustments.

An approaching bird presents a greater challenge than a bird travelling across a plane at roughly constant distance. The former demands continual focus changes, and the latter tests the ability to hold a narrow frame on the subject. Rapid changes in distance, light and background still defeat individual frames in a sequence.

Aperture and Available Light

Maximum aperture changes from f/5 at 100mm to f/6.3 at 400mm. That difference forms part of the trade-off behind the lens’s reach and manageable physical size. A sunny reserve, open coast or daytime sports field gives room to use a shutter speed suited to movement. Dense woodland at dawn places greater demands on camera sensitivity. Extending the focal length supplies no extra light; the narrower maximum aperture at the far end reduces it.

For a perched bird, careful support and stabilisation permit a slower shutter speed. A flying bird often requires a much faster exposure, with ISO rising to compensate. Higher ISO performance depends on the camera and acceptable output size. Subject distance creates another limit: a bird recorded through warm air over water often lacks fine detail even with accurate focus and a fast shutter. A clearer position often improves detail beyond another increase in focal length.

The nine-blade circular diaphragm influences the appearance of out-of-focus areas, but subject separation depends on distance relationships. A nearby bird against distant foliage stands clear of its surroundings at f/6.3. A bird pressed close to a hedge remains visually tangled with the leaves behind it. The M.Zuiko 50-200mm F2.8 IS Pro brings a brighter aperture for closer subjects, at the cost of this lens’s long-end reach.

Optical Construction and Backlit Scenes

OM System specifies 21 elements in 15 groups, including ED and high-refractive glass. ZERO coating addresses internal reflections, and a fluorine layer on the front element helps remove water droplets and dirt. A distant bird against a bright sky exposes colour fringing and flare readily, so those design choices have a clear purpose. Their presence alone leaves measured edge-to-edge sharpness unproven without controlled first-hand testing.

At 400mm, the final level of detail also depends on shutter speed, focus placement, atmospheric conditions and any crop made later. A sharp optical design cannot recover detail lost to heat haze. Likewise, an image made across a long stretch of water often shows less feather texture than one made much closer under the same equipment settings. The narrow field still demands fieldcraft and proximity.

Ideal Use Cases for This Lens

Perched Birds and Birds in Flight

Small birds commonly remain distant or retreat as a photographer approaches. The 400mm end offers a narrow field for birds on branches, waders across shallow water and raptors resting beyond a path. Starting wider helps locate a bird before tightening the frame, particularly when it launches unexpectedly. For flight, the zoom ring allows the composition to adapt as the bird approaches or turns. The OM System OM-1 Mark II body supplies bird recognition and forms a supported Sync IS pairing.

Lighting changes rapidly around birds. A pale subject against the sky demands different exposure from the same bird crossing dark trees. The viewfinder appears steady through Sync IS even when the animal’s movement still requires a short exposure. The bird photography camera considerations cover the body-side tracking demands of this work. The tripod foot supports stationary sessions in a hide, leaving handheld operation for faster encounters on a walk.

Mammals and Larger Wildlife

Deer at a woodland edge, seals offshore and animals across open ground benefit from the 200-800mm-equivalent framing. The 100mm end becomes valuable when a larger subject moves close enough to exceed a tight frame. At 400mm, the lens isolates an eye or head from a safe, respectful position, though real working distance varies with the size of the animal and the final crop needed.

Low light presents a particular issue for woodland mammals. The lens’s f/6.3 maximum at the long end means faster animal movement pushes ISO high. A smaller OM System OM-5 Mark II body keeps a walking setup compact, but the camera’s controls and high-ISO output still influence the result. The wider wildlife camera system discussion covers tracking and burst depth alongside reach.

Outdoor Sport and Motorsport

The range covers athletes and vehicles at changing distances from a fixed position. A runner far along a track fills a greater part of the frame near 400mm, then remains within the composition as the zoom moves towards 100mm. The same flexibility suits field sports when play moves across the pitch. A body with reliable subject tracking and sufficient burst depth helps exploit the brief moments when action, light and framing align.

Stabilisation supports panning and precise framing, though a moving athlete still requires a suitable shutter speed. Intentional motion blur calls for a different exposure decision from a crisp action frame. The M.Zuiko 40-150mm F4 Pro covers nearby sport in a smaller kit; a distant runner or vehicle exposes its shorter reach. The 100-400mm earns its strongest role on pitches, tracks and circuits with enough light for a fast shutter.

Butterflies, Dragonflies and Distant Close-Ups

The minimum focusing distance reaches 1.3m across the zoom range. At 400mm, maximum actual reproduction measures 0.29×, corresponding to 0.57× full-frame-equivalent framing. A butterfly resting beyond arm’s reach or a dragonfly on a reed therefore occupies a useful part of the frame without the front of the lens intruding into its space. That close-focus capability adds value to a wildlife walk, but the lens stops short of the 1:1 optical reproduction associated with a dedicated macro optic.

For tiny insect anatomy or a subject requiring much greater reproduction, the M.Zuiko 90mm F3.5 Macro IS Pro serves a different purpose. The 100-400mm excels when distance and a cautious approach take priority. Its field of view also makes surrounding vegetation easier to exclude, provided enough room remains between the subject and its background.

Handling, Balance and Weather Protection

OM System quotes 1,125g without the tripod mount, lens caps or hood. With the mount attached, the quoted weight rises to 1,300g. That mount provides a better support point for a long lens than attaching a tripod solely beneath a small camera body. Its redesigned foot accepts Arca-Swiss-type clamps and detaches with the lens still attached to the camera. The revised arrangement also gives a useful grip when carrying the combination between shooting positions.

At about 206mm long in its specified configuration, the lens fits into a field bag with less difficulty than its 800mm-equivalent angle might imply. It still occupies considerable space beside a body, spare battery, weather cover and support. A compact OM System OM-3 body changes the feel of the combination, with much of the weight in the lens. Supporting the barrel during handheld work reduces strain on the camera mount and provides steadier control of the zoom.

IPX1-rated splash protection and dust-resistant construction suit light rain and spray with a suitably protected camera and accessories. The rating offers no underwater protection or immunity from prolonged heavy rain. A fluorine-coated front surface makes routine cleaning easier after droplets, dust or fingerprints. Weather protection applies to the complete working setup only when the other attached components offer compatible protection.

Advanced Features and Camera Integration

The Micro Four Thirds mount fits compatible OM System, Olympus and Panasonic Micro Four Thirds bodies. Physical mounting and coordinated stabilisation remain separate questions. OM System’s five-axis Sync IS depends on a supported camera combination. On another body, the lens retains its own optical stabilisation, subject to the camera’s settings and compatibility. The headline seven-stop result belongs to a specified pairing and focal length, not every body at 400mm.

An OM-1 Mark II kit with the 12-40mm F2.8 Pro II gives a body and standard zoom for general photographs, with this 100-400mm covering distant subjects. Camera-side bird recognition, drive speed and autofocus settings belong to the body. The lens contributes long focal length, stabilisation and focus-range controls; it has no independent wireless transfer or recording features.

The Panasonic Leica DG Vario-Elmar 100-400mm II shares the Micro Four Thirds mount and nominal 100-400mm range. Each manufacturer’s stabilisation system behaves differently across bodies. The OM lens’s five-axis Sync IS advantage depends on supported OM System equipment, so physical fit alone never guarantees the stated correction.

A complete field setup includes a camera, spare power, weather cover, suitable support and a bag accommodating the hooded lens. Teleconverters extend reach but also increase demands on light and focusing. Nearby mammals seldom justify a converter; distant birds in open habitats provide a stronger reason for one.

Teleconverter Options and Their Limits

The lens accepts OM System’s MC-14 and MC-20 teleconverters. With the MC-14, the focal-length range gives approximately 280-1120mm full-frame-equivalent framing and a maximum aperture of f/7.1-9. The M.Zuiko MC-20 2.0x teleconverter extends framing to approximately 400-1600mm equivalent, with a maximum aperture of f/10-13. Both accessories remain separate from the standard lens package.

At 1600mm-equivalent framing, locating and holding a moving bird inside the viewfinder becomes substantially harder. The f/13 maximum aperture at the long end leaves much less light for a fast shutter, especially under cloud or tree cover. Atmospheric distortion also erases the extra detail that the converter aims to record. The MC-20 therefore makes the clearest sense with sufficient light, a cooperative subject and a body capable of focusing under the resulting conditions.

Converters affect close-up framing too. At the 400mm end, OM System lists 0.40× actual reproduction with MC-14 and 0.57× with MC-20, corresponding to approximately 0.81× and 1.15× full-frame-equivalent framing. Those values improve the size of a distant insect or flower in the frame, but do not transform the bare lens into a 1:1 optical macro design. The stronger converter trades aperture and handling ease for that tighter view.

The smaller change in framing with MC-14 makes it the easier converter for subjects that shift position. At the 400mm setting, the combined 560mm actual focal length narrows the view to the equivalent of 1120mm on full frame, with f/9 as the widest available aperture. A bird already difficult to locate at 400mm becomes harder to track through that tighter field. The useful question in the field concerns the detail gained against the light lost: a nearby subject in weak light favours the bare lens, whereas a still bird across an open, bright shoreline gives the converter a clearer role. Distance and air quality remain decisive in both cases.

Position in the OM System Lens Range

A Smaller Walking Kit

The M.Zuiko ED 75-300mm F4.8-6.7 II occupies a smaller, shorter-reaching position for a Micro Four Thirds walking kit. The 100-400mm IS II extends the long end to 400mm and brings coordinated stabilisation on supported bodies, IPX1-rated splash protection and a tripod mount. The difference matters most when small birds routinely remain beyond the useful framing of 300mm.

Longer Native Reach

At the other end of the range, the M.Zuiko Digital ED 150-600mm F5.0-6.3 IS extends native focal length beyond this lens. That longer zoom suits frequent work with particularly distant subjects, with an associated increase in the size and weight of the equipment carried. The M.Zuiko 150-400mm F4.5 TC1.25x IS Pro occupies a specialised position, pairing a brighter constant aperture with premium construction and a built-in converter. These lenses address different carrying budgets and working methods, despite their overlapping telephoto roles.

An Outdoor Kit Beyond the Telephoto

A super-telephoto rarely covers an entire day of photography by itself. An animal close to the path, a wide view of its habitat or a family photograph during travel all call for a shorter lens. The M.Zuiko Digital ED 12-100mm F4 IS Pro covers the general scenes that begin below this 100mm zoom’s range. A two-lens kit handles mixed travel with greater flexibility.

The lens hood, cap and detachable foot also affect packing. A compartment needs room for the mounted camera and the barrel without constant pressure on the mount; measurements for the bare lens alone give an incomplete picture of the carried kit. During long walks, a strap attached to a suitable lens-side support distributes the load better than a strap supporting the entire combination from a small camera. During a stationary session, the foot supplies a natural balance point on a compatible support. The 72mm filter thread accepts filters of that diameter, with the hood still useful against stray light.

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FAQs

Changes from the original OM System 100-400mm

The second generation adds five-axis Sync IS compatibility with supported OM System bodies, a fluorine-coated front element and a revised tripod mount. The 100-400mm focal length, f/5-6.3 maximum aperture and 1.3m minimum focusing distance remain.

How much stabilisation at 400mm?

OM System specifies up to 5.5 stops through Sync IS at 400mm with a supported camera under its test conditions. Its up-to-seven-stop figure applies at 100mm. Lens-only correction carries a separate 4.5-stop rating.

Will this lens fit a Panasonic Micro Four Thirds camera?

The Micro Four Thirds mount permits use on compatible Panasonic bodies. OM System’s stated coordinated Sync IS performance requires a supported OM System body, so stabilisation behaviour varies by combination.

Does the MC-20 make this a 1600mm lens?

The compatible 2× converter produces an 800mm actual focal length at the long end, giving approximately 1600mm full-frame-equivalent framing on Micro Four Thirds. The combination’s maximum aperture at that setting becomes f/13.

Does stabilisation freeze birds in flight?

No. It reduces camera movement and steadies framing. A bird’s movement still requires a suitable shutter speed and responsive camera tracking.