The Sony Zeiss Sonnar T* FE 55mm F1.8 ZA is a standard prime lens for Sony’s mirrorless cameras, and corrected for use on full-frame bodies. Announced alongside the original A7 bodies in October 2013, it delivers close to standard 50mm coverage for a normal perspective, and a bright f1.8 focal ratio for isolating the subject against a blurred background.
The FE 55mm f1.8 ZA was one of the first lenses for Sony’s full-frame mirrorless cameras, and it remains a popular premium choice due in part to its compact size. It has since been joined by a selection of 50mm primes from Sony: the Zeiss Planar T* FE 50mm f1.4 ZA represents a higher-end choice with a price around 50% more, while the FE 50mm f1.8 is a budget option at around one quarter of the price.
For this review I tested all three of these standard Sony lenses on the 42MP Sony A7R II camera body. I also included the Sigma 50mm f1.4 Art as an interesting third party alternative. So if you’re interested in which standard prime lens to choose for your Sony mirrorless system, you’ve come to the right place!
Check prices on the Sony FE 55mm f1.8 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!
Facts from the catalog
As usual I’ll have a look at the technical data of the Sony FE 55mm f1.8 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 Sony FE 50mm f1.8, the Sony FE 50mm f1.4 ZA and the Sigma 50mm f1.4 Art (“Sigma Art” for short).
Size (diameter x length): At 64 x 71mm (2.5 x 2.8in.) plus 49mm for the lens hood (77mm diameter) the Sony FE 55mm f1.8 ZA is a bit longer than the FE 50mm f1.8 (69 x 60mm + 26mm lens hood) although it is still a small lens. The FE 50mm f1.4 ZA is much larger at 83 x 108mm + 53mm lens hood. And that lens is even topped by the Sigma Art which shows its heritage as a DSLR design at 85 x 126mm + 47mm lens hood. [+]
Weight: 281g (9.9oz.) plus 41g for the lens hood. The Sony FE 50mm f1.8 is only 166g + 18g lens hood, the FE 50mm f1.4 ZA is 780g + 33g lens hood. The Sigma Art is the heaviest lens in this comparison at 910g plus 43g for the lens hood. [+]
Optics: The lens is a simple design with only 7 elements in 5 groups but it has three aspherical elements.The Sony FE 50mm f1.8 has 6 lenses in 5 groups while both the FE 50mm f1.4 ZA and the Sigma Art are more complex designs with 12/9 resp. 13/8 elements/groups [+]
Closest focus distance is 0.49m (19in.) in manual focus with a magnification of 1:6.9. This is similar to the other Sony lenses in this comparison. Only the Sigma Art offers a slightly better magnification of 1:5.4 at 0.38m distance. The Sony FE 55mm f1.8 ZA achieves a magnification of 1:10 at 0.67m distance. 
Filter-thread: 49mm, just like the FE 50mm f1.8. The FE 50mm f1.4 ZA needs 72mm filters, the Sigma Art takes 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 has a non-linear gearing that allows for precise manual focus but makes smooth focus pulling for videographers almost impossible. Only the FE 50mm f1.4 ZA and the Sigma Art have linear gearing. The three Sony lenses have no distance or dof markings. Focus on the Sigma Art works differently as it has a direct linear mechanical coupling between the focus ring and the focus action. It 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 currently sells at around 830 EUR (incl. 19% VAT) / 1000 USD. The FE 50mm f1.8 sells at 200 EUR / 250 USD, the FE 50mm f1.4 ZA is the most expensive of the four lenses at 1500 EUR / 1500 USD, while the Sigma Art goes for 700 EUR / 850 USD. 
The Sony FE 55mm f1.8 ZA comes with a soft pouch and the lens hood is included and is reversible for transport. That’s the same as with the FE 50mm f1.4 ZA while the FE 50mm f1.8 comes without pouch. The Sigma Art comes equipped with a nice padded pouch but no strap. 
Aperture ring: Of the four lenses only the Sony FE 50mm f1.4 ZA offers an aperture ring with 1/3 stop clicks which can be turned off for continuous, smooth, and noise-free operation. 
Sealing: Both Sony ZA lenses have special weather-sealing throughout the construction but lack a rubber sealing at the lens-mount. The Sony FE 50mm f1.8 is not especially sealed, just like the Sigma Art. [+]
The score in the “features-department” is 0[-]/5/7[+], the most prominent features of the lens being that it’s pretty small, light, and well protected against the elements.
If you want a standard lens (45 to 58mm focal length) with a focal ratio of at least f2.0 and autofocus for Sony E-mount full-frame cameras there are quite a few options to consider, mostly at the 50mm length. Keep in mind though that actual 50mm lenses are slightly wider than 55mm and you have to crop 10% to achieve the same angle of view, which in turn would reduce the resolution of a 42MP full-frame image to 35MP. That said, unless you’re comparing them side-by-side, a 50mm is going to feel a lot like a 55.
- Sony has two alternatives: the small and cheap FE 50mm f1.8 from 2016 for 200 EUR / 250 USD (see my Sony FE 50mm f1.8 review which I’ll be completing shortly). And there is the FE 50mm f1.4 ZA from 2016 for 1500 EUR/USD. It is much bigger and heavier than the FE 55/1.8 ZA but also offers 2/3 of a stop better light-gathering power. It earned a Highly Recommended in my Sony FE 50mm f1.4 ZA review.
- Sigma offers their 50mm f1.4 Art lens for 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 even shorter focal lengths. To get the angle-of-view of a 55mm lens from a 40mm though it needs a 38% crop which means almost halving resolution:
- 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 your effective resolution of a 42MP full-frame sensor to 27MP.
- 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 Loxia Planar T* 50mm f2.0 from 2014 which is manual focus only. It sells for 750 EUR / 950 USD. And there is the Zeiss Batis 40mm f2.0 CF from 2018 which offers autofocus and has a very impressive close-focus capability. It costs 1200 EUR / 1300 USD and came Highly Recommended in my Zeiss Batis 40mm f2.0 CF review.
How big is the difference between 50mm and 55mm focal length? Here is the angle of view that the Sony FE 50mm f1.8 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 97,6% in Reikan FoCal) with no outliers over a series of 40 shots. There is a slight focus variation whether the lens focuses from a closer distance or from infinity.
The lens focuses in around 0.7 sec on a Sony A7R II from infinity to 0.67m (1:10 magnification), which is relatively fast and comparable to the Sony FE 50mm f1.8 and the Sigma Art (on a Nikon Z7 with FTZ adapter). The Sony FE 50mm f1.4 ZA takes almost 1 sec. The focus ring of the FE 55mm f1.8 ZA is 21mm wide. It moves very smoothly and can easily be operated with one finger. Both other Sony lenses also offers very smooth focus by wire 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 only the FE 50/1.8 registers a tiny bit of noise. The Sigma Art produces an audible focus noise. As you pull focus, you’ll notice some focus breathing: the image of the Sony FE 55mm f1.8 ZA becomes 7% more magnified when I adjusted the focus from infinity to 0.67m. This could be distracting when shooting videos but is par for the course: the other lenses in this comparison all increase their magnification between 7% and 11%.
Next check out my quality results!Check prices on the Sony FE 55mm f1.8 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!