Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T* Lab Test Review
The FE 55mm F1.8 ZA Carl Zeiss Sonnar T* is one of the first three lenses available for Sony's full-frame E-mount system, having been announced alongside the Alpha 7 and 7R camera bodies. It's a slightly long 'normal' prime designed for everyday photography, and its relatively fast F1.8 aperture makes it a good choice for selective focus work or shooting in low light. Its 7-element, 5-group optical design includes three aspherical elements to minimise aberrations, which is unusual for this type of lens.
The 55mm is a large-ish lens for its type (it's 71mm / 2.8" long), but even so, when coupled with the A7 or A7R it's still more compact than comparable full frame SLR options (as the cameras themselves are slimmer). It's also decidedly expensive, at around $999 / £910 / €940 at the time of writing. It's pretty clear that this isn't going to be quite the same proposition as the inexpensive 50mm F1.8 primes available for full frame SLRs - indeed it costs several times as much as the average 50mm F1.4.
The FE 55mm F1.8 can also be used on Sony's APS-C E-mount bodies, on which it will behave like a classic short telephoto 'portrait' lens. However most users of these cameras will probably find the Sony E 50mm F1.8 OSS to be a better choice, as it's much cheaper and includes optical image stabilisation, while offering decent optical quality too.
- 55mm focal length
- Fast F1.8 maximum aperture
- FE lens for full frame Sony E-mount cameras (also works on APS-C E-mount models)
Lens test data
The 55mm F1.8 lives up to its Carl Zeiss branding, returning truly superb test results on the Alpha 7R. It's extremely sharp, shows little chromatic aberration or distortion, and has entirely acceptable levels of vignetting. In fact it comes very close indeed to the astounding (but $4000) Zeiss Otus 55mm F1.4.
|Sharpness||Sharpness is simply spectacular. At F1.8 the 55mm is impressively sharp, outperforming the 50mm F1.8s for Canon and Nikon SLRs by a substantial margin (and the 50mm F1.4s for that matter, too). It just gets better on stopping down; at F4 and F5.6, central sharpness is literally off the charts (helped here by being tested on the 36MP, AA filterless A7R). Diffraction takes the edge off sharpness at F22, as usual, but this setting should still be perfectly usable when depth of field is a priority.|
|Chromatic Aberration||Chromatic aberration is pretty low. There'll be some green/magenta fringing visible towards the extreme corners of the frame if you look closely, but it's unlikely to be hugely objectionable. It will be automatically corrected in the camera's JPEGs, too.|
|Vignetting||Vignetting is kept pretty well under control, at 1.6 stops wide open, which is perfectly respectable for a fast prime. The falloff profile is rather gradual too, which tends to make any vignetting less visually objectionable.|
|Distortion||Distortion is extremely low, with just a little barrel-type visible if you look closely. This will also be corrected automatically by the camera when shooting JPEG.|
The scale of Sony's achievement here becomes clear when comparing the FE 55mm F1.8 directly to the Zeiss Otus 55mm F1.4, which lays a strong claim to being the best lens for which we have test data. The Otus still just about comes out on top - it measures as slightly sharper wide open - but it's unlikely any difference will be particularly visible in real-world photography. The Otus also just about wins out on chromatic aberration and distortion, but overall the Sony can certainly wear its Zeiss badge with pride.
Compared to the Canon EF 50mm f/1.8 II or Nikon AF-S Nikkor 50mm f/1.8G, the Sony is quite simply in a different class in terms of wide-open sharpness. This is only to be expected, given its much higher price and far more modern design, but it does give some idea of why Sony feels it can charge a premium for the lens. The Zeiss also beats Nikon's latest, and even-more-pricey AF-S Nikkor 58mm f/1.4G for sharpness in these tests - it really is very good indeed.
From the lab test results, the Sony FE 55mm F1.8 ZA is quite simply one of the sharpest lenses we've seen. It's clearly been designed with the demands of modern high resolution sensors in mind, and is easily a match for the currently class-leading resolution of the Alpha 7R. It's impossible to ignore its price, but in this case, there's a pretty good argument that you get what you pay for.
Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T* specifications
|Lens type||Prime lens|
|Max Format size||35mm FF|
|Focal length||55 mm|
|Lens mount||Sony FE|
|Number of diaphragm blades||9|
|Special elements / coatings||3 aspherical elements|
|Minimum focus||0.50 m (19.69″)|
|Motor type||Stepper motor|
|Full time manual||Unknown|
|Weight||281 g (0.62 lb)|
|Diameter||64 mm (2.52″)|
|Length||71 mm (2.8″)|
|Zoom method||Rotary (internal)|
|Filter thread||49.0 mm|
|Hood product code||ALC-SH131|
This lens review uses DxOMark data thanks to a partnership between dpreview.com and DxO Labs (read more about DxOMark and our partnership with DxO Labs). DxOMark is the trusted industry standard for independent image quality measurements and ratings. DxOMark has established this reputation with its rigorous hardware testing, industry-grade laboratory tools, and database of thousands of camera, lens and mobile test results. Full test results for this lens can be found at www.dxomark.com.