In summary
By our estimate, this lens is the pick of the crop. Performance-wise, the third lens in Olympus’s PRO range is every bit as good as the flagship model and significantly better than the cheaper lens.
Offering the advantage of significantly better weather resistance, it will likely become a vital member of a two-lens kit for the OM-1 camera, along with the recently-released M.Zuiko Digital 12-40mm f/2.8 PRO II lens. This combination would give photographers a range of focal lengths from the equivalent of 24mm to 300mm, which will encompass most popular genres.
Full review
The third model in the M.Zuiko Digital 40-150mm line-up of lenses from OM Digital Solutions sits between the original 40-150mm f/4-5.6 lens and the faster, significantly larger and more expensive 40-150mm f/2.8 PRO lens, offering a mid-sized, mid-priced and, likely more popular alternative. Designed to complement the new OM-1 camera, it features the same IP53 weather-resistance rating and also supports the Focus Stacking function the OM-1 camera, including with the High Res Shot mode.
Angled view of the M.Zuiko Digital 40-150mm f/4 PRO lens. (Source: OM Digital Solutions.)
IP53-rated weather resistance, a constant f/4 maximum aperture and a minimum focus distance of 70 cm across the focal length range make this lens an ideal partner for the recently-released OM-1 camera. Like the OM-1, it can operate safely in temperatures as low as -10 degrees Celsius.
The optical diagram shows the positions of the exotic elements in the new lens. (Source: OM Digital Solutions.)
The optical design of the new lens (shown above) includes 15 elements in nine groups, among them two ED lenses, one Super ED lens, one HR lens and two aspherical lens elements, as shown in the diagram above. It also features ZERO (Zuiko Extra-low Reflection Optical) coating to minimise ghosting and flare and has a scratch-resistant fluorine coating on the front element that repels water, oil, and dust for easy cleaning.
Claimed as the most compact and lightweight fixed aperture telephoto zoom lens available at the time of release, the new lens has a retracting mechanism and internal zooming to maintain a constant length while in use, as shown in the diagram above. This design minimises centre-of-gravity changes while zooming and keeps the weight of the lens well-balanced.
A cutaway view of the M.Zuiko Digital ED 40-150mm f/4 PRO lens. (Source: OM Digital Solutions.)
The M.Zuiko Digital 40-150mm f/4 PRO lens is supplied with front and end caps plus a cylindrical LH-66E lens hood, wrapping cloth, printed instruction manual and warranty card. It accepts 62 mm diameter filters.
Who’s it For?
The 40-150mm range covers the same focal lengths as an 80-300mm lens on a full-frame camera. Price-wise the new lens sits between two significantly older lenses covering the same zoom range: the original 40-150mm f/4-5.6 II lens, which is slower but considerably lighter and cheaper and the larger, faster and more expensive M.Zuiko Digital 40-150mm f/2.8 PRO lens.
As expected, the 40-150mm f/4-5.6 II lens is not weather-resistant, while the 40-150mm f/2.8 PRO lens only meets IPX1 standard. This makes the M.Zuiko Digital ED 40-150mm f/4 PRO lens the best choice for photographers who spend much of their time outdoors, especially in inclement weather (although it must be used on a similarly weather-resistant camera like the OM-1 to gain full advantage of the superior sealing, which is shown in the diagram below).
The extensive weather-resistant sealing in the M.Zuiko Digital ED 40-150mm f/4 PRO lens. (Source: OM Digital Solutions.)
The table below compares key specifications of the three lenses.
| 40-150mm f/4 PRO | 40-150mm f/4-5.6 R | 40-150mm f/2.8 PRO | |
| Announced | February 2022 | June 2011 | September 2014 |
| Extends while zooming | No – but must be extended before use | Yes | No |
| Minimum aperture | f/22 | ||
| Lens construction | 15 elements in 9 groups | 15 elements in 11 groups | 16 elements in 10 groups |
| Exotic elements | 2 ED, 1 super ED, 1 HR and 2 aspherical | 1 DSA, 1 aspherical ED, 1 ED, 3 HR | 1 aspherical ED, 2 aspherical, 1 SED, 3ED, 1HD |
| Optical coatings | fluorine coating on front element | ZERO (Zuiko Extra-low Reflection Optical) Coating | |
| Diaphragm Blades | 7 | 9 | |
| Weather resistance | IP53 standard | None | IPX1 standard |
| Focus drive | Stepping motor (MSC) | Screw drive micromotor (MSC) | Dual linear motors (VCM) |
| MF clutch mechanism | No | No | Yes |
| Minimum focus | 70 cm | 33 cm | 70 cm |
| Maximum magnification | 0.21x | 0.22x | 0.21x |
| Filter size | 62 mm | 58 mm | 72 mm |
| Dimensions (Diameter x L) | 68.9 x 99.4 mm (124 mm long when in use) | 63.5 x 83 mm
(150mm long at 150mm) |
79.4 x 160mm |
| Weight | 382 grams | 220 grams | 760 grams (880 g with tripod adapter) |
| Lens hood supplied | Yes, LH-66E | Yes, LH-61C | Yes, LH-76 |
| Tripod collar supplied | No | No | Yes |
| Compatible with teleconverters | No | No | Yes |
| RRP (AU$) | $1499 | $349 | $2099 |
The 24-300mm (35mm equivalent) zoom range is ideal for genres as diverse as portraiture and sports and wildlife photography. It can also be used for street shooting and taking candid shots of family and friends.
The minimum focusing distance of 70 cm across the entire zoom range provides a maximum magnification of 0.41x at the 150mm focal length. The constant f/4 maximum aperture provides scope for differential focusing with soft, de-focused backgrounds, particularly with longer focal lengths.
Build and Ergonomics
The lens barrels are mostly made from lightweight metal with plastic used for adjustment rings and other such niceties. Despite its small size and light weight it feels solidly constructed and comfortable to operate. It also felt well balanced on the OM-D E-M1 II camera body we used for our tests.
Interestingly for a PRO series lens, it lacks the focus-clutch mechanism that makes switching between auto and manual focusing fast and easy. Nor does it have a function button on the lens, although the latest cameras more than compensate with an abundance of programmable controls. Furthermore, in common with most other lenses in the f/4 range, the new lens can’t be used with either of the company’s two teleconverters.
The inner barrel is not motorised and must be extended by turning the zoom ring from the retracted position, indicated by a white dot on the metal ring just behind the zoom ring that also carries the focal length settings. This extends the inner barrel by approximately 25 mm.
This diagram shows the internal zooming operation within the retracting lens barrel. (Source: OM Digital Solutions.)
Extending the focal length further doesn’t change the overall length of the lens as shown in the illustration above. The lens is retracted again by turning the ring back to the index position. This requires a little force as it crosses the 40mm setting.
The front section of the inner barrel is approximately 10 mm wide. Its outer rim has a bayonet fitting for the supplied lens hood. The front element of the lens is roughly 40 mm in diameter and surrounded by a matte black annulus that is roughly 8 mm wide. This is recessed by a couple of millimetres to allow for the threading that accepts 62 mm filters.
The leading edge of the outer barrel has a 7 mm wide metal band that carries the branding details of the lens plus a narrow blue ring. Directly behind it is the focusing ring, which is 11 mm wide and totally covered in fine moulded ridges to provide a secure grip.
The focusing ring turns through 360 degrees since focusing is driven from the camera. It turns freely when the camera is set to manual focus mode but provides little in the way of tactile feedback.
Roughly three millimetres aft of the focusing ring lies the zoom ring, which is 542 mm wide and has six narrow, closely-spaced bands of moulded ridging to provide a secure grip. A sloping, 4 mm wide metal band around its rear carries the focal length settings for 40mm, 50mm, 70mm, 100mm and 150mm, while the white retraction index mark lies 22 mm to the left of the 40mm position.
Moving from 40mm to 150mm turns the zoom ring through approximately 20 degrees and there’s a click-stop at 40mm before the ring can be turned to the retraction index. A second branding label, in larger characters than on the ring at the front of the outer barrel, is engraved on the 20 mm wide section of the barrel that leads to the solid, chromed lens mount.
Surrounding the mount is a rubber flange that excludes moisture and dust. Eleven gold-plated contacts inside the lens mount carry signals between the lens and the camera.
The supplied cylindrical lens hood is 50 mm deep with a finely-ridged inner surface to suppress potential reflections. It has a locking button and can be reversed over the lens for transport and storage.
Performance
Subjective assessments of test shots showed the review lens to be a good performer, delivering excellent sharpness and vibrant colour rendition. Imatest confirmed our subjective assessments for the focal lengths we were able to test (due to the limitations of our testing set-up).
Our Imatest tests were conducted with all internal optical corrections disabled since Olympus (and subsequently, OM Digital Solutions) applies automatic corrections to JPEGs and also embeds them in raw files, where they can be ‘read’ by most file conversion software. The highest resolution recorded in our Imatest tests was with the 50mm focal length at an aperture of f/5, where centre resolution was just above expectations for the test camera’s 20-megapixel sensor for JPEGs (and substantially higher for ORF.RAW files, which were converted into 16-bit TIFF files with Adobe Camera Raw, our preferred raw file converter.
While JPEG resolution fell a little below expectations in measurements taken half way and three-quarters of the way out from the centre, for converted raw files, resolution remained above expectations across the frame. The other focal lengths, except for 135mm (the longest we were able to measure) were almost as good.
We found it remarkable that high resolutions remained consistent across most focal lengths from f/4 through to f/11, where diffraction begins to take effect.. The graph below provides the results of our tests.
Edge softening was also relatively consistent across the same aperture range, which is also noteworthy. On the basis of our measurements we’d advise photographers against stopping this lens down beyond f/10. We’d also recommend shooting raw files wherever possible to take full advantage of the lens’s capabilities.
Lateral chromatic aberration remained mainly within the negligible band, straying into the low band with the 40mm focal length at the smallest aperture settings. But we found no visible coloured fringing in any of our test shots so we don’t see it as a major problem. In the graph below showing the results of our tests, the red line marks the border between negligible and low CA.
Vignetting (edge and corner shading) and rectilinear distortion were also negligible for all practical purposes. At 150mm traces of corner shading could be seen at f/4 but they had disappeared by f/5.6 and no vignetting was evident thereafter.
Similarly, with in-camera corrections disabled, slight pincushion distortion was present at 100mm and 150mm, although no other distortion was obvious at shorter focal lengths. Since the in-camera corrections effectively address both problems, neither issue is of real concern.
Autofocusing was remarkably fast and super-accurate as well as being almost silent, which makes this lens a good choice for ‘stealth’ shooting of wildlife and also for use when shooting movies. It took less than 0.2 seconds on average to rack from the closest focus to infinity.
Although not classified as a macro lens, the 40-150mm f/4 PRO lens has similar close-focusing capabilities to the more expensive f/2.8 lens. At the minimum focus of 70 cm the reproduction ratio of 0.21x is close-up shots of flowers and small animals.
Bokeh was nice and smooth when backgrounds were evenly-lit. However, we noticed a tendency to outline bright highlights, especially if the aperture was stopped down a little.
Normal backlighting was impressively handled and the generous lens hood and ZERO coatings provided very good flare resistance. However, if a very bright light source was within the frame, the lens could be forced to flare, producing colourful flare artefacts.
Shooting sunstars at f/22 was difficult with this lens, although not totally impossible. We had greater success with raw files since they provided more scope for adjustments of image tones, as shown in the examples in the Samples section of this review.
Conclusion
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SPECS
Picture angle: 30 to 8.2 degrees (diagonal)
Minimum aperture: f/22
Lens construction: 15 elements in 9 groups (including (2 ED, 1 super ED, 1 HR and 2 aspherical elements); coatings
Lens mounts: Micro Four Thirds
Diaphragm Blades: 7 (rounded aperture)
Weather resistance: Yes, to IEC 60529 IP53 standard
Focus drive: High-speed imager AF (MSC) using stepping motor
Stabilisation: No; relies on camera’s IBIS
Minimum focus: 70 cm
Maximum magnification: 0.21x at 150mm
Filter size: 62 mm
Dimensions (Diameter x L): 68.9 x 99.4 mm
Weight: 382 grams
Standard Accessories: Front and end caps, lens hood (LH-66E), wrapping cloth
Distributor: OM Digital Solutions Australia Pty Ltd, Ph: 1300 659 678
TESTS
Based on JPEG files from the Olympus OM-D E-M1 Mark II.
Based on ORF.RAW files recorded simultaneously and converted into 16-bit TIFF format with Adobe Camera Raw.
SAMPLES
Vignetting at f/4, 40mm focal length.
Vignetting at f/4, 50mm focal length.
Vignetting at f/4, 70mm focal length.
Vignetting at f/4, 100mm focal length
Vignetting at f/4, 150mm focal length.
Rectilinear distortion at 40mm focal length.
Rectilinear distortion at 50mm focal length.
Rectilinear distortion at 70mm focal length.
Rectilinear distortion at 100mm focal length.
Rectilinear distortion at 150mm focal length.
40mm focal length, ISO 100, 1/30 second at f/11.
50mm focal length, ISO 100, 1/30 second at f/11.
70mm focal length, ISO 100, 1/30 second at f/11.
100mm focal length, ISO 100, 1/25 second at f/11.
150mm focal length, ISO 100, 1/25 second at f/11.
Close-up at 40mm; ISO 100, 1/250 second at f/4.
Close-up at 150mm; ISO 100, 1/320 second at f/4.
Close-up with even lighting; 85mm focal length, ISO 100, 1/125 second at f/4.
Backlit close-up; 111mm focal length, ISO 100, 1/50 second at f/18.
Backlit close-up; 70mm focal length, ISO 100, 1/40 second at f/16.
Backlit close-up; 97mm focal length, ISO 100, 1/400 second at f/4.
Backlit close-up with small, diffuse sunstar; 106mm focal length, ISO 100, 1/60 second at f/22.
Flare artefacts in a contre-jour raw file shot at 70mm focal length, ISO 100, 1/320 second at f/16.
A similar shot showing flare and a sunstar in a JPEG original; 70mm focal length, ISO 100, 1/250 second at f/22.
Sunstar at 40mm focal length; ISO 100, 1/160 second at f/22. (taken from a raw file).
Strong backlighting; 70mm focal length, ISO 200, 1/2500 second at f/8.
150mm focal length, ISO 100, 1/100 second at f/5.
150mm focal length, ISO 100, 1/160 second at f/4.
40mm focal length, ISO 200, 1/500 second at f/8.
40mm focal length, ISO 200, 1/800 second at f/11.
150mm focal length, ISO 200, 1/1250 second at f/9.
150mm focal length, ISO 200, 1/1000 second at f/8.
40mm focal length, ISO 200, 1/400 second at f/9.
97mm focal length, ISO 200, 1/1600 second at f/10.
150mm focal length, ISO 200, 1/1250 second at f/9.
150mm focal length, ISO 200, 1/1250 second at f/9.
140mm focal length, ISO 100, 1/40 second at f/7.1.
40mm focal length, ISO 100, 1/15 second at f/8.
50mm focal length, ISO 200, 1/60 second at f/5.
135mm focal length, ISO 100, 1/4 second at f/18.
Rating
RRP: AU$1499
- Build: 9.0
- Handling: 8.9
- Image quality: 8.9
- Autofocusing: 9.1
- Versatility: 8.9
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