The Sony Zeiss Planar T* FE 50mm F1.4 ZA is a prime lens for Sony’s mirrorless cameras, and corrected for use on full-frame bodies. Announced in July 2017, its optical design is from Zeiss and it delivers standard 50mm coverage for a normal perspective, and a bright f1.4 focal ratio for isolating the subject against a blurred background. This is brighter by 2/3 of a stop than the Sony FE 55mm f1.8 ZA or Sony FE 50mm f1.8 which allows for better background isolation and shorter shutter speeds and/or lower ISO values.
As the FE 50mm f1.4 ZA is not exactly cheap at 1500 EUR/USD it is expected to perform on a very high level. To find out whether this holds true I tested its optical qualities on the 42MP Sony A7R II camera body against several other lenses, including the Zeiss Otus 55mm f1.4 (my current reference standard lens) and the Sigma 50mm f1.4 Art (a cheaper alternative now available in the e-mount). So if you’re interested in which high performance standard prime lens to choose for your Sony mirrorless system, you’ve come to the right place!
Facts from the catalog
As usual I’ll have a look at the technical data of the Sony FE 50mm f1.4 ZA first. I’ve rated the features with a [+] (or [++]), when it’s better than average or even state of the art, a  if it’s standard or just average, and [-] if there’s a disadvantage. For comparison I use the the Sony FE 55mm f1.8 ZA, the Sigma 50mm f1.4 Art (“Sigma Art” for short) and the Zeiss Otus 55mm f1.4 (“Zeiss Otus”).
Size (diameter x length): At 83 x 108mm (3.3 x 4.3in.) plus 53mm for the lens hood (92mm diameter) the Sony FE 50mm f1.4 ZA is much larger than the FE 55mm f1.8 ZA (64 x 71mm +49mm lens hood). Yet it is even topped by the Sigma Art (85 x 126mm + 47mm lens hood) and the Zeiss Otus (92 x 117mm + 32mm lens hood) which shows their heritage as a DSLR design. And the Zeiss Otus becomes even longer when you add the necessary adapter to mount it on an E-mount body. 
Weight: 780g (27.5oz.) plus 33g for the lens hood. The FE 55mm f1.8 ZA is much lighter at 281g + 41g lens hood but then it only has a focal ratio of f1.8. The Sigma Art is 910g + 43g lens hood and the Zeiss Otus weighs 945g + 64g lens hood not counting the necessary adapter. 
Optics: The lens is a pretty complex design with 12 elements (including one aspherical) in 9 groups. But this is par for the course with the Sigma Art and the Zeiss Otus sporting 13/8 resp. 12/10 elements/groups. The Sony FE 55mm f1.8 ZA is a much simpler design with only 7 elements in 5 groups but it has three aspherical elements. [+]
Closest focus distance is 0.45m (18in.) in manual focus with a magnification of 1:6.3. The FE 55mm f1.8 ZA and the Zeiss Otus offer slightly less magnification of 1:6.9 resp. 1:6.8. Only the Sigma Art is slightly better offering 1:5.4 magnification at 0.38m distance. The Sony FE 50mm f1.4 ZA achieves a magnification of 1:10 at 0.63m distance. 
Filter-thread: 72mm, while the FE 55mm f1.8 ZA uses 49mm filter. The Sigma Art and the Zeiss Otus take 77mm filters. [+]
Image stabilization: No optical stabilization of the lens. The Sony A7 Mark II bodies onwards provide built-in sensor-shift stabilization. Same with the other lenses in this comparison. 
Auto focus: Built-in AF drive. Manual-focus override is by simply turning the focus ring. The focus ring operates as focus-by-wire but it has a linear gearing which makes smooth focus pulling for videographers easy. The FE 55mm f1.8 ZA has non-linear focus-by-wire and like the FE 50mm f1.4 ZA has no distance or dof markings. Focus on the Sigma Art and Zeiss Otus works differently as both have a direct linear mechanical coupling between the focus ring and the focus action. They also offers the distance and dof markings that normally come with lenses designed for DSLRs. [+]
Covers full frame/FX or smaller. Same with the alternatives. [+]
Price: The lens sells at around 1500 EUR (incl. 19% VAT) / 1500 USD. The FE 55mm f1.8 ZA is 830 EUR / 1000 USD, while the Sigma Art goes for 700 EUR / 850 USD which makes it the cheapest alternative at the high-end. The Zeiss Otus is the most expensive of the four lenses at 3200 EUR / 4000 USD. 
Both Sony ZA lenses come with a soft pouch and the lens hood is included and is reversible for transport. The Sigma Art comes equipped with a nice padded pouch but no strap while the Zeiss Otus comes without pouch. 
Aperture ring: yes, with 1/3 stop clicks which can be turned off for continuous, smooth, and noise-free operation. The Zeiss Otus also has an aperture ring but it offers only 1/2 stop clicks which cannot be turned off. [+]
Sealing: Both Sony ZA lenses have special weather-sealing throughout the construction but lack a rubber sealing at the lens-mount. The Zeiss Otus and the Sigma Art are not especially sealed. [+]
The score in the “features-department” is 0[-]/6/6[+], the most prominent features of the lens being its de-clickable aperture ring and its protection against the elements.
If you want a standard lens (45 to 58mm focal length) with an f1.4 focal ratio and autofocus for Sony E-mount full-frame cameras there are only two alternatives:
- Sigma offers their 50mm f1.4 Art lens for the E-mount since 2018. It’s an optical design from 2014 and came Highly Recommended in my Sigma 50mm f1.4 Art review when tested on a 36MP Nikon D800 in 2014. It is around 50% cheaper than Sony’s 50mm f1.4 ZA.
- Samyang has the AF 50mm 1.4 FE from 2016 which sells for 480 EUR/USD.
Other alternatives include manual focus lenses or lenses with slower focal ratios or shorter focal length:
- Sigma has their 40mm f1.4 Art now also available for E-mount for 1200 EUR / 1400 USD. The lens is huge and heavy but optically excellent. See my Sigma 40mm f1.4 Art review where it earned a Highly Recommended. With its shorter focal length you have to crop 25% to achieve the same angle of view as a 50mm lens which reduces the resolution of a 42MP full-frame image to 27MP.
- Sony offers the FE 55mm f1.8 ZA for 830 EUR / 1000 USD. It is a much smaller and lighter lens than its bigger sibling but you lose 2/3 of a stop of light gathering power and suffer some reduction in background isolation. I’ll be soon completing my Sony FE 55mm f1.8 ZA review. There’s also the budget but basic FE 50mm f1.8 to consider.
- Samyang has several manual focus 50mm lenses one of which is the 50mm 1.4 AS UMC which sells for around 350 EUR/USD.
- Zeiss offers the 55mm f1.4 Otus from 2013 which is manual focus only and can be used on an EF to E-Mount adapter. It sells for 3200 EUR / 4000 USD. See my Zeiss Otus 55mm f1.4 review where it earned a Highly Recommended. Zeiss also offers the manual focus Loxia 50mm f2 and the autofocus Batis 40mm f2.
How big is the difference between 50mm and 55mm focal length? Here is the angle of view that the Sony FE 50mm f1.4 ZA covers on a full-frame body compared to the FE 55mm f1.8 ZA:
Focus accuracy and repeatability is critical to consistently produce sharp shots especially with large aperture lenses. Repeatability (the accuracy of focus on the same subject after repeated focus-acquisition) of this lens is very good (measured 98.4% in Reikan FoCal) with no outliers over a series of 40 shots. There is only a very slight focus variation whether the lens focuses from a closer distance or from infinity.
The lens focuses in around 0.9 sec on a Sony A7R II from infinity to 0.63m (1:10 magnification), which is relatively slow. The Sony FE 55mm f1.8 ZA and the Sigma Art (on a Nikon Z7 with FTZ adapter) move in around 0.7 resp. 0.6 sec. The focus ring of the FE 50mm f1.4 ZA is 33mm wide. It moves very smoothly and can easily be operated with one finger just like the FE 55mm f1.8 ZA. The Zeiss Otus also has a silky smooth AF operation. Only the Sigma Art has a much stiffer mechanical coupling between the focus ring and the focus action.
AF-operation of the Sony lenses in this comparison is inaudible from the outside and if you record video with the built-in microphone. The Sigma Art produces an audible focus noise. As you pull focus, you’ll notice some focus breathing: the image of the Sony FE 50mm f1.4 ZA becomes 7% more magnified when I adjusted the focus from infinity to 0.63m. This could be distracting when shooting videos but is par for the course: the other lenses in this comparison all increase their magnification between 5% and 7%.
Next check out my quality results!Check prices on the Sony FE 50mm f1.4 ZA at Amazon, B&H, Adorama or WEX. Alternatively get yourself a copy of my In Camera book or treat me to a coffee! Thanks!