In summary
Panasonic’s Lumix G 42.5mm f/1.7 ASPH./POWER O.I.S. lens is a strong performer that delivers sharp images across most of its aperture range. Edge-to-edge sharpness of frames is very good for such a fast lens and other potential aberrations are either negligible or very well controlled.
This lens is a good choice for any of Panasonic’s G-series cameras and also usable on any Olympus M4/3 body.
Full review
The Lumix G 42.5mm f/1.7 ASPH./POWER O.I.S. lens is Panasonic’s second M4/3 lens with this focal length, the first being the Lumix DG Leica Nocticron 42.5mm f/1.2 ASPH Power O.I.S, which we reviewed in February 2014. These fast medium-telephoto prime lenses are designed primarily for portraiture but can also be used wherever a shallow depth of field is desirable. Both lenses cover the same angle of view as an 85mm lens on a 35mm camera and include POWER O.I.S. stabilisation.
Angled view of the Lumix G 42.5mm f/1.7 ASPH./POWER O.I.S. lens without front and end caps and hood. (Source: Panasonic.)
The optical design of Panasonic’s 42.5mm f/1.7 lens consists of 10 elements in eight groups, with a single aspherical element to control spherical aberration and distortion. A seven-bladed iris diaphragm produces a circular aperture for smooth out-of-focus blurring at wide aperture settings.
The diagram above shows the positions of the exotic elements in the optical design of the lens. (Source: Panasonic.)
The review lens is a full f-stop slower than the Leica-branded lens we reviewed previously, which has a number of consequences. While both lenses cover the same angle of view and both include the same AF motor and stabilisation technology, the optical design of the faster lens is more complex and its front element is significantly larger (to collect more light). More and larger glass elements make the faster lens more than three times the weight of the f/1.7 lens.
The slower (and cheaper) lens has a few additional advantages, aside from its much lighter weight and smaller size. It can focus closer than the f/1.2 lens and its aperture range extends to f/22 (which may not be as advantageous as it might seem). The table below compares key specifications of both lenses.
|
|
Lumix G 42.5mm f/1.7 |
Lumix DG Leica Nocticron 42.5mm f/1.2 |
|
Picture angle |
29 degrees |
|
|
Minimum aperture |
f/22 |
f/16 |
|
Lens construction |
10 elements in 8 groups |
14 elements in 11 groups |
|
Exotic elements |
one aspherical lens |
2 aspherical lenses, 1 ED lens, 1 UHR lens |
|
Diaphragm Blades |
7 (circular aperture) |
9 (circular aperture) |
|
Focus drive |
Stepping motor |
|
|
Minimum focus |
31 cm |
50 cm |
|
Maximum magnification |
0.4x in 35mm equivalent |
0.2x (35mm camera equivalent) |
|
Filter size |
37 mm |
67 mm |
|
Dimensions (Diameter x L) |
55 x 50 mm |
74 x 76.8 mm |
|
Weight |
130 grams |
425 grams |
|
RRP |
|
AU$2,299 |
Introducing a new 42.5mm f/1.7 lens into an already crowded market sector shows how successful the Micro Four Thirds format has become for potential lens buyers. As well as Panasonic’s f/1.2 42.5mm lens, both Panasonic and Olympus offer 45mm prime lenses that cover almost the same angle of view.
The Panasonic 45mm lens is an f/2.8 macro lens (RRP AU$1099), while the Olympus offers a straightforward 45mm f/1.8 prime at only AU$499 (RRP). Olympus lenses tend to be smaller, lighter and cheaper because they’re not stabilised since stabilisation is built into the camera bodies.
The lens is supplied with a cylindrical lens hood plus front and end caps, all made from solid plastic. A soft carrying pouch is provided.
Who’s it for?
In brief: M4/3 photographers who want a fast portrait lens but can’t afford the very high cost of the Panasonic f/1.2 42.5mm lens. Being small and light, it also has some potential for travel photography, where it can be handy for portraiture, close-ups and casual street shots. This lens can be used on other M4/3 cameras, including Olympus models.
Build and Ergonomics
The build quality of this lens is much as you would expect from a mid-range prime lens. It has a solid metal mount and the barrel appears to be made from metal but is finished with high-quality polycarbonate.
A ‘decoration ring’ made from hard black plastic covers the bayonet mounting for the lens hood. It must be removed before the hood can be fitted, which is a hassle as you have to find somewhere to store it. The cylindrical lens hood clips neatly into the bayonet mounting and can be reversed over the lens barrel for transport and storage.
Only one control surface is provided: the focusing ring, which is 18 mm wide and mostly clad with fine ribbing. The ring turns smoothly through a full circle without changing the length of the lens or rotating the front element. Manual focusing is ‘by wire’; i.e. driven by the camera, which means minimal tactile feedback.
Eleven gold-plated contacts carry signals between the camera and the lens. Autofocusing is also driven from the camera, using a stepping motor which supports a 240 frames/second data transfer rate to deliver fast responses with the Contrast AF systems in Panasonic G-series cameras. It’s also quiet enough to be used while recording movie clips.
The integrated MEGA O.I.S. stabiliser can compensate for both small, fast jitters and large, slow movements and provides a high level of stability for both low light still shooting and recording movie clips indoors (or in other poorly-lit situations). The lens is threaded to accept 37 mm diameters filters.
Performance
Out of interest (and because we had both cameras at hand), we decided to run separate tests of the review lens on both Olympus OM-D E-M1 and a Panasonic GH4 camera bodies. The results were quite similar, although the E-M1 produced higher resolution in our Imatest tests, probably because it offered a ‘low’ ISO setting equivalent to ISO 100, whereas the lowest sensitivity available on the GH4 was ISO 200.
Both cameras produced resolution levels that exceeded expectations for their sensors’ 15.9 megapixel resolution, with the highest resolution for each camera being at f/4. Some edge softening was found at wider apertures, although this was largely resolved by f/4 with the E-M1 and f/5.6 with the GH4. Diffraction reduced resolution from about f/8 onwards, as shown in the graph of our Imatest results, below.
Lateral chromatic aberration was negligible with both camera bodies. In the graph of our results below, the red line separates negligible and low CA.
The only signs of coloured fringing in test shots occurred in association with very strong backlighting when we were testing the lens for flare. Areas close to the edges of the frame ““ which commonly reveal coloured fringing due to chromatic aberration ““ had no coloured fringing.
Vignetting could be seen in shots taken with apertures between f/1.7 and f/2.5, after which it became difficult to detect. Distortion was effectively non-existent, even without in-camera correction.
Contre-jour lighting was handled very well. It was just possible to force the lens to flare by including a bright light source in the frame, but with normal backlit subjects, flare was minimal and contrast and colour saturation were well maintained.
The minimum focusing distance of 31 cm makes this lens suitable for shooting close-ups of larger flowers and similar items. Thanks to the fast maximum aperture, bokeh at the widest aperture settings was nice and smooth.
Conclusion
Panasonic’s Lumix G 42.5mm f/1.7 ASPH./POWER O.I.S. lens is a strong performer that delivers sharp images across most of its aperture range. Edge-to-edge sharpness of frames is very good for such a fast lens and other potential aberrations are either negligible or very well controlled.
This lens is a good choice for any of Panasonic’s G-series cameras and also usable on any Olympus M4/3 body. Its price is competitive for its build quality and specifications and shopping around should be advantageous once the lens has been in stores for a while. Importing the lens from off-shore re-sellers won’t provide a worthwhile price reduction, given the current dollar conversion ratio.
SPECS
Picture angle: 29 degrees
Minimum aperture: f/22
Lens construction: 10 elements in 8 groups (including one aspherical lens element)
Lens mounts: Micro Four Thirds
Diaphragm Blades: 7 (circular aperture)
Focus drive: Stepping motor
Stabilisation: POWER O.I.S.
Minimum focus: 31 cm
Maximum magnification: 0.2x (0.4x in 35mm equivalent)
Filter size: 37 mm
Dimensions (Diameter x L): 55 x 50 mm
Weight: Approx. 130 grams
Standard Accessories: Front and rear caps, lens hood, soft carrying pouch
TESTS
Based on JPEG files taken with the Panasonic GH4 camera.
Based on JPEG files taken with the Olympus OM-D E-M1 camera.
SAMPLES
Vignetting at f/1.7. (Taken from an uncorrected raw file.)
Rectilinear distortion. (Taken from an uncorrected raw file.)
Slight flare in a shot with a bright light source inside the frame; ISO 100, 1/500 second at f/4.
A crop from the above image, enlarged to 100%, showing the flare-related coloured fringing.
A similar-sized crop from the edge of the frame that confirms the purple fringing is not associated with chromatic aberration.
Normal backlighting with the light source just outside the frame; ISO 200, 1/640 second at f/4.5.
Close-up at f/1.7; ISO 100, 1/250 second.
Close-up at f/2.5; ISO 200, 1/1250 second.
ISO 800, 1/1000 second at f/10.
ISO 200, 1/500 second at f/3.5.
ISO 200, 1/100 second at f/1.8.
ISO 400, 1/200 second at f/3.2.
ISO 100, 1/250 second at f/4.
ISO 400, 1/100 second at f/4.5.
ISO 320, 1/60 second at f/5.6.
ISO 400, 1/400 second at f/3.5.
ISO 400, 1/1000 second at f/5.6.
ISO 200, 1/100 second at f/7.1.
Rating
RRP: AU $549; US$400
- Build: 8.8
- Handling: 8.8
- Image quality: 9.0
- Versatility: 8.8