In summary
The Lumix S PRO 50mm f/1.4 is a professional lens and both knowledge and care are required to get the best out of it. We’d recommend experimenting with the various AF modes and customisable AF settings until you become accustomed to how the lens will perform in different shooting situations.
Single-shot AF worked particularly well in our shooting tests. Continuous AF needed to be customised to specific moving subjects but, once that was done, it also proved effective.
Full review
The Lumix S PRO 50mm f/1.4 (S-X50) is the first prime lens Panasonic has released for its S1 and S1R cameras and claims to be a ‘reference-quality’ model that ‘sets a new benchmark in image quality’. Its fast f/1.4 maximum aperture is made possible through use of a substantial amount of glass in its construction, which makes this lens both rather large and very heavy for its type. Like other s-series lenses it is solidly built and dust- and splash-resistant.
Angled view of the Lumix S PRO 50mm f/1.4 without end caps or lens hood. (Source: Panasonic.)
The optical design of this lens contains 13 elements in 11 groups, including two aspherical lenses and three ED (Extra-low Dispersion) lenses. These exotic elements are used to suppress both axial chromatic aberration and chromatic aberration of magnification, while the aspherical elements are also used for correcting astigmatism and achieving high resolution.
The optical design of the 50mm f/1.4 lens showing the positions of the exotic glass elements. (Source: Panasonic.)
This lens is distinguished by a double focus system that combines a linear motor and stepping motor. Panasonic claims the drive achieves a maximum speed of 480 fps for fast, high-precision AF based on its proprietary, contrast-based DFD (Depth From Defocus) technology. Focus breathing (small changes in effective focal length when changing between near and distant focus) is also suppressed.
The focus clutch mechanism can be engaged by pushing the focusing ring forwards for autofocusing or pulling it back to focus manually, in a similar fashion to the system used on Olympus M4/3 lenses. This enables instant AF/MF switching along with precise manual focusing.
An 11-bladed iris diaphragm closes to a circular aperture to ensure attractive bokeh, particularly at the minimum focusing distance of 44 cm. Conveniently, this lens accepts 77 mm diameter filters, the same size as the 24-105mm zoom lens.
This lens is supplied with the regular front and end caps plus a deep, petal-shaped lens hood that attaches via a bayonet mounting and can be reversed over the lens barrel for transport and storage. A soft carrying pouch is also provided.
Who’s it For?
‘Nifty Fifty’ lenses have been popular since the birth of 35mm photography and enjoyed a resurgence in recent years. Used with a 36 x 24 mm sensor, this focal length is useful across a wide range of subject types, from event photography to landscapes, fashion, product, street and travel shooting. But its 44 cm minimum focusing distance won’t suit macro shooting, although it could be used for shooting close-ups of larger flowers and pets.
Lens speed usually comes with both size and price limitations. Interestingly, the main players in the ‘full frame’ mirrorless camera all have similarly specified lenses on offer. The table below, listed in alphabetical order, provides a quick comparison.
| Brand | Maximum aperture | Diameter x length | Weight | Estimated price* |
| Canon | f/1.2 | 89.8 x 108 mm | 950 grams | AU$3599 |
| Nikon | f/1.8 | 76 x 86.5 mm | 415 grams | AU$1050 |
| Panasonic | f/1.4 | 90 x 130 mm | 955 grams | AU$3599 |
| Sony | f/1.4 | 83.5 x 108 mm | 778 grams | AU$2299 |
* Manufacturer’s RRP used where available.
This lens requires care when using it since the depth of field at the maximum aperture is razor-thin at the minimum focusing distance. Having such a fast lens can tempt users to select it, even when a smaller aperture is more advisable.
Build and Ergonomics
This is a large, solidly constructed and relatively weighty lens and its build quality reflects these qualities. The size and weight of this lens are appropriate for the two S1-series camera bodies but they also present some challenges for users of this lens.
On the positive side is the fact that it’s easier to hold heavier lenses steadily while taking long exposures hand-held. But on the negative side is the fact that holding and carrying the total weight of roughly two kilograms (camera body plus lens plus battery and cards) is tiring.
The large maximum aperture of this lens can also present problems when shooting with it wide open, since the depth of focus for close-ups (which is when you’ll want to shoot at f/1.4) is paper thin. Deviate by a millimetre from the sharpest focus and the shot is likely to be unusable.
Unfortunately, Panasonic doesn’t specify what materials this lens is made from although an extensive search online suggests magnesium alloy could be a key component. The finish is similar to the other lenses in the three lenses released initially with the S1 and S1R cameras.
So is the environmental sealing. The rubber sealing ring around the lens mount is wide enough to keep out moisture and dust. The lens barrel has a matte black coating that looks professional.
The focusing ring is well defined and sits towards the front of the lens barrel, beginning about 17 mm back from its leading edge. There’s a deepish gully between the front of the ring and the front section of the lens, which allows the ring to rotate without affecting the rest of the lens.
The front section of the ring is covered by a 19 mm wide strip of fine rubber ridging that provide a secure and comfortable grip. With focusing being driven from the camera, this ring rotates full circle when power is off.
The trailing edge dips down slightly and extends for about 5 mm before coming up against a 24 mm wide section of the lens barrel that separates the focusing ring from the aperture ring. This part of the lens barrel has a raised band that carries the name of the lens.
Behind the focusing ring is a 14 mm wide, with the last two thirds of the band carrying both grip ridges and focal length settings from f/4 to f/16 in one-stop increments. Click stops are provided at one-third stop intervals throughout the aperture range.
The final portion of the outer barrel consists of a 28 mm long flat section carrying the white index mark against which the aperture settings are lined up. Behind it, the outer barrel slopes in to end in the lens mount.
There are no controls on this section of the barrel and the lens lacks both a distance scale and a depth of field indicator. There was nothing on the lens to say where the lens is manufactured.
Performance
While we tested this lens on both the S1 and S1R camera bodies, we’ve used the results from the S1 for this review to maintain consistency with the other lens reviews. We’ve also provided results from raw files taken at the same time, again in the interests of consistency.
Imatest showed this lens to be capable of meeting expectations for the sensor’s resolution with JPEG files in the centre of the frame and comfortably exceeding the expected resolution with raw files. Edge resolution fell a little short with JPEG files but was well above expectations for raw files. The graph below shows the result of our Imatest tests on JPEG files.
Edge softening was substantial at apertures between f/1.4 and f/4.0, which is expected for such a fast lens. The highest resolution recorded was at f/4.0, the point at which the discrepancies between central and edge resolution began to reduce.
Lateral chromatic aberration remained entirely within the ‘negligible’ band for JPEGs, as shown in the graph of our results above, in which the red line marks the boundary between ‘negligible’ and ‘low’ CA. Checks of a few raw files (where CA is not corrected) showed it to be slightly higher on the whole, but still within the low-to-negligible range.
We found no evidence of coloured fringing in either JPEGs or converted raw files shot with this lens. This issue is largely irrelevant since both Panasonic S1 cameras provide in-camera corrections for coloured fringing, as do most raw file converters.
The same is true for aberrations like vignetting and rectilinear distortion, where we had to assess performance by using uncorrected raw files. Vignetting was obvious at f/1.4 but had largely disappeared by f/2.2. Rectilinear distortion was effectively negligible.
The review lens highly resistant to ghosting and flare, even when a bright light source was included within the frame. No flare artefacts were generated and there was minimal loss of contrast. Normally backlit shots were rendered with full colour and tonal fidelity.
Bokeh was a mixed bag and dependent upon the background lighting. With evenly-lit backgrounds it was very smooth and attractive. Traces of outlined highlights could be found in unevenly-lit backgrounds.
Close focusing capabilities are limited by the 44 cm minimum focusing distance, which restricts subject options to larger flowers and medium-sized animals. But the fast maximum aperture makes this lens ideal for portraits where selective focus can be used to advantage.
Autofocusing was generally fast and very quiet and it was possible to use shutter speeds as slow as 1/10 second with the camera hand-held and obtain a high percentage of sharp images.
Conclusion
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SPECS
Picture angle: 47 degrees
Minimum aperture: f/16
Lens construction: 13 elements in 11 groups (including 3 aspherical and 3 extra-low dispersion elements)
Lens mounts: L-Mount
Diaphragm Blades: 11 (circular aperture)
Focus drive: Linear motor plus stepping motor with internal focusing
Stabilisation: No, Complies with Lumix camera Body I.S. and 5-Axis Dual I.S.2
Minimum focus: 44 cm
Maximum magnification: 0.15x
Filter size: 77 mm
Dimensions (Diameter x L): 90 x 130 mm
Weight: 955 grams
Standard Accessories: Lens front and end caps, lens hood, lens storage bag
Distributor: Panasonic Australia, Ph. 132 600; www.panasonic.com.au
TESTS
Based on JPEG files taken with the Lumix DC-S1 camera.
Results from RW2.RAW files captured simultaneously.
SAMPLES
Vignetting.
Rectilinear distortion.
ISO 100, 1/125 second at f/8.
ISO 100, 1/4000 second at f/1.4.
ISO 100, 1/4000 second at f/1.4.
ISO 100, 1/4000 second at f/1.4.
Very strong backlighting; ISO 200, 1/4000 second at f/5.6.
Stabilisation test; ISO 400, 1/10 second at f/7.1.
ISO 100, 1/640 second at f/3.5.
ISO 100, 1/500 second at f/3.2.
ISO 100, 1/80 second at f/5.6.
ISO 100, 1/320 second at f/5.
ISO 100, 1/160 second at f/5.
ISO 100, 1/80 second at f/4.5.
ISO 100, 1/400 second at f/2.8.
ISO 1600, 1/20 second at f/6.3.
ISO 1250, 1/40 second at f/6.3.
ISO 6400, 1/20 second at f/9.
Additional image samples can be found with our reviews of the Lumix S1 and S1R cameras.
Rating
RRP: AU$3599; US$2299
- Build: 9.2
- Handling: 8.5
- Image quality: 9.0
- Versatility: 8.5
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