Olympus M.Zuiko Digital 17mm f/1.8 Lens

      Photo Review 8.8
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      In summary

      Buy this lens if:
       – You require a fast wide-angle lens for general-purpose use.
       – You’d like a lens that provides a flat enough field of coverage to be used for copying.
      – You’d like a lens that requires no readjustment when you fit polarisers and graduated filters.

      Full review

      The new M.Zuiko Digital 17mm f/1.8 wide-angle lens isn’t the first 17mm lens Olympus has produced for its PEN and OM-D cameras. But it’s the fastest and one of the fastest in the Olympus stable.   The other lens is a pancake-type lens that’s only 22mm long but has a maximum aperture of f/2.8. Both lenses offer a classical focal length equivalent to 34mm in 35mm format, which is popular for a wide variety of applications.

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      The M.Zuiko Digital 17mm f/1.8 lens shown without end caps and lens hood. (Source: Olympus.)

      Although not as compact as the pancake lens, the f/1.8 lens is relatively small and light for a prime lens, extending just 35.5 mm in front of the camera body and weighing only 120 grams. Its optical design nine lens elements  in six groups and includes three aspherical elements (one of them a Dual Super Aspherical type) to correct chromatic aberrations plus an HR (High Refractive index) lens with high spherical aberration correction.  

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      The diagram above shows the location of the exotic elements. Olympus’ proprietary high-end ZERO multi-coating technology, which halves the reflectance of wavelengths between 450 and 650 nm, has also been applied to minimise the effects of flare and ghosting.

      The autofocusing system is based on Olympus’s proprietary MSC (Movie & Still Compatible) mechanism, which drives focusing directly  by using a precision-finished metal shaft and feed screw, rather than a geared mechanism (which causes operating noise). Only three small, lightweight lens elements are moved, ensuring smooth autofocusing with high speed and low noise.  

      The Snapshot Focus mechanism developed for the M.Zuiko Digital ED 12mm f/2.0 lens has been incorporated in the  new 17mm lens.  With this mechanism, sliding the focus ring back towards  the camera switches the focus to a manual mode and sets the focus to a specific distance (indicated on the inner barrel, which is revealed). Users can adjust the focus manually by simply turning the focus ring.

      With the focus ring slid forward, the lens is set for autofocusing and the focusing mode is set by the camera. Snapshot Focus can be used for quick pan-focus shooting, in which both subject and background are in focus.

      The lens is supplied with front and end caps plus an instruction manual and warranty card. The end cap supplied with the lens is a bayonet-type mounting, which is easy to attach and remove quickly. The LH-48B lens hood is an optional extra, as usual for Olympus lenses.

      Build and Ergonomics
      The all-metal barrel design  creates an impression of durability and quality and the solid chromed mounting plate attaches the lens firmly to the camera. Eleven gold-plated electronic connections inside the lens mount provide connections to OM-D and PEN cameras. This lens will also work with Panasonic’s Lumix G Micro series camera bodies (which aren’t stabilised).

      Being a prime lens, the 17mm f/1.8 lens has only one control surface: the focusing ring. It’s approximately 8 mm wide and situated roughly 13 mm behind the front of the lens barrel.  In front of the focus ring is a depth of field scale, which shows the range of distances that will be acceptably sharp at different aperture settings.

      In the Snapshot Focus position, this scale can be used in association with the distance marks in metres and feet engraved on the inner barrel. Moving between the autofocus position (with the ring pushed forward) and the Snapshot Focus position is a bit too easy and you can often find the lens won’t focus because you’ve set Snapshot Focus inadvertently. We would like to have seen a little more resistance   to overcome.

      The focusing ring turns through approximately 50 degrees in the Snapshot Focus position but rotates through the full circle in the AF setting. The mechanism isn’t geared to match the speed at which the ring is rotated so the only feedback to the user when focusing manually is what’s shown on the monitor screen.

      The barrel contracts slightly just behind the grip band. Behind it is a raised band that is approximately 5 mm wide and has grip mouldings on opposite sides to make it easy to change lenses.

      Performance
      We tested the review lens on two camera bodies, the PEN E-PM2 (which is reviewed separately) and the OM-D E-M5. It performed better on the latter camera so we’ve used those results as the basis for this review. Autofocusing was as fast as the camera supports and generally very quiet, making this lens ideal for use when shooting movie clips.

      Subjective assessment of shots straight from the camera showed them to be a little soft. However, they became ‘sharp as a tack’ after very modest unsharp masking in Photoshop.

      Imatest confirmed this assessment and showed JPEG files from the E-M5 to be close to meeting expectations for the camera’s 15.9-megapixel sensor, despite under-sharpening. The highest resolution figures came between about   f/2.8 and f/5.6, with a steep falling off from f/8 on, as shown in the graph of our test results below.
       

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       Lateral chromatic aberration was low to moderate. In the graph of our Imatest tests below, the red line marks the boundary between negligible and low CA values, while the green line separates low from moderate CA and the pink line is the edge of the ‘severe’ CA level.

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      A relatively high level of chromatic aberration isn’t desirable, as Olympus cameras don’t have in-camera correction for this flaw. However, if you shoot raw files most converters include it and it’s easy to carry out and usually effective.

      In practice, coloured fringing was relatively slight and only seen towards the edges of image frames. It also only became visible in contrasty lighting, so we don’t consider it to be a major issue.

      Vignetting at maximum apertures was barely noticeable. Rectilinear distortion was also well controlled. Bokeh was quite good, considering the sensor size of the camera and the focal length of the lens.

      Buy this lens if:
       – You require a fast wide-angle lens for general-purpose use.
       – You’d like a lens that provides a flat enough field of coverage to be used for copying.
      – You’d like a lens that requires no readjustment when you fit polarisers and graduated filters.

      SPECS

       Picture angle: 65 degrees
       Minimum aperture: f/22
       Lens construction: 9 elements in 6 Groups (one DSA element, two aspherical elements, one HR element)
       Lens mounts: Micro Four Thirds
       Diaphragm Blades: 7 (circular aperture)
       Focus drive: High-speed Imager AF (MSC)
       Stabilisation: No (Olympus cameras have in-body stabilisation)
       Minimum focus: 25 cm
       Maximum magnification: 0.08x (0.16x 35mm equivalent)
       Filter size:   46 mm
       Dimensions (Diameter x L): 57.5 x 35.5mm
      Weight:  120 grams

      TESTS

      (based on JPEG files from the Olympus OM-D E-M5.)

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      SAMPLES

       
       

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      Vignetting at f/1.8.
       
       

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      Rectilinear distortion.

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      Depth of field at f/1.8.

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      Depth of field at f/3.5.
       
       

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      Depth of field at f/5.6.
       
       

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      Depth of field at f/11.
       
       

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      012: Depth of field at f/22.
       
       

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      Close-up; ISO 200, 1/125 second at f/5.
       
       

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      Portrait; ISO 400, 1/500 second at f/6.3.
       
       

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      ISO 200, 1/400 second at f/9.
       
       

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      Crop from the above image enlarged to 100% showing coloured fringing and edge softening.
       
       

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      Slight flare at ISO 200, 1/250 second at f/8.
       
       

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      ISO 400, 1/250 second at f/9.
       
      Additional image samples can be found with our review of the Olympus PEN E-PM2.

      Rating

      RRP: AU$599; US$500

      • Build: 9.0
      • Handling: 8.5
      • Image quality: 8.5
      • Versatility: 8.5

      Buy