Personally, I drive a Volkswagen Golf. And if there's a Ferrari Testarossa in front of the door, of course, the question arises of how much faster that can go. Curious and with sweaty palms – you don't want to fly off the road during the test – I crept behind the wheel of a Ferrari to figure that out. Fortunately, this is not a website about cars. The Ferrari that I was talking about was a Sony FE 55 mm f/1.8 Carl Zeiss Sonnar, in combination with the Sony A7R and its 36-megapixel, full-frame sensor.
The Sony FE 55 mm Sonnar T* FE F1.8 ZA is one of the first FE lenses available for the two spectacular full-frame mirrorless cameras (Sony A7 and Sony A7R) that appeared at the end of 2013.
This bright, fixed-focal length lens is universally usable, with which you immediately think of low-light situations or creating a beautiful background blur. With a suggested retail price of 1,000 euros, this is not a cheap lens. The Sony Zeiss lenses, recognizable by the blue logo on the side of the lens, are the showpieces of the Sony lens stable. How well they would perform?
Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T with a Sony A7R
Construction and autofocus
This lens breathes luxury and has a very nicely executed, dust- and moisture-resistant, matte black metal body. It comes with a lens pouch and a metal lens hood. The new FE mount fits on both Sony cameras with a full-frame sensor (Sony A7R) and on Sony cameras with an APS-C Sensor (Sony A77). For a standard lens, the Sony 55 mm f/1.8 Zeiss is relatively long (71 mm), which is further accentuated if you used the included lens hood. The lens hood is reversed for transport on the lens, but then you can no longer focus well manually. The lens body weighs nearly 3 ounces, is made of metal and has a broad focus ring that turns deliciously smooth. Manual focusing is done with a focus-by-wire system, which means that there is no hard stop at infinity or the shortest setting distance (50 cm).
Vignetting is, as with virtually all lenses on a full-frame sensor, in some practice shots visible at maximum aperture. At maximum aperture, the vignetting is just over 1 aperture stop, after 1 stop stopping down cut in half. On this point, I would classify the Sony 55 mm 1.8 Zeiss as good/very good, instead of first class. Fortunately, vignetting is easy to correct with software, if you do have trouble with it.
In our measurement results from lab test shots, the vignetting in jpg files is slightly higher than in RAW files. We see the same phenomenon when testing with a Canon camera, and this may have to do with the in-camera conversion from RAW to jpg.
Distortion is absent. And that is not because it's corrected by the camera. We measure 0.1% barrel distortion in uncorrected RAW files. That's not visible to the naked eye. Perfect.
The original T* surface coating works with Carl Zeiss ' advanced optical design and suppresses internal reflection in the inside of the lens. This guarantees, according to Sony, strong contrast with bright accents and deep blacks – a typical feature of the top-class Zeiss lenses. However, in extreme situations such as night shots or direct backlighting, ghosts will appear, such as the night shot on the right shows. I would also rate the Sony 55 mm 1.8 Zeiss here as good/very good.
The Sony 55 mm f/1.8 Zeiss makes maximal use of the 36 megapixels of the Sony A7R. With this combination, you actually make sharper images than with an exceptional lens on a camera with a 24 megapixel sensor, although you will have to significantly magnify the image to see the differences.
This lens delivers sharp images, starting from full aperture, from the center to the corners. You see the sharpness increase after 1 stop stopping down, but the sharpness is also very high at maximum aperture, which is accentuated by the beautiful background blur. The highest sharpness we measured after stopping down 2 stops, but with the naked eye I see no difference in sharpness between recordings made with an aperture between f/2.8 and f/11.
You don't generally achieve this enormously high sharpness. It's best when photographing from a tripod. If you shoot with this lens on a Sony A7R by hand, then make sure that you have a shutter speed of 1/125 second or faster. At slower shutter speeds, you run a big risk of losing some resolution to motion blur. Given the high resolving power of this lens, that isn't that bad.
Tip: If you use the 50 ISO setting of the Sony A7R, not only do you get low-noise, very natural looking files, but you can use the longer f/1.8 for a beautiful background blur, without fear of overexposure. One stop difference is more than you think.
Image cutout of a 50 ISO picture made at f/5.6, 1/160 sec
Click (2x) on the image for a larger version, shown at 100%
The Sony FE 55 mm f/1.8 Zeiss is a surprising design that contains only 7 elements in 5 groups. In its simplicity, it shows its mastery. There are various aspherical lenses applied to combat aberrations. And that design was successful: we looked at the chromatic aberration in uncorrected RAW files (many cameras automatically correct chromatic aberration in jpg files, meaning you're not looking at the pure performance of the lens), then the measured values for the Sony 55 mm 1.8 is among the best 5 (of the 700) measurement results that we now have.
A good lens design ensures a complete absence of lateral chromatic aberration.
The Sony 55mm f.18 Zeiss on the Sony A7R with its full-frame sensor offers at maximum aperture a beautiful bokeh thanks to the 9 aperture blades from which it's built. From vignetting, the bokeh has a cat's eye character in the corners, as with virtually all lenses we've tested on a full-frame sensor. On the right, you'll see that there's even a tiny bit of an onion pattern just barely visible in the bokeh. That phenomenon we see more often in very sharp lenses with aspherical lenses, and in this case it's definitely not disruptive. Also the shift from sharp to unsharp runs very naturally. Here you see the enlarged version of the above practice shot.
Conclusion Sony FE 55mm F1.8 ZA Carl Zeiss Sonnar T test with a Sony A7R
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WYSIWYG score: This table shows the performance of this lens when you store the files in the camera as jpg, with all available in-camera lens corrections applied. This score gives you for this lens/test camera combination: "What you see is what you get".
Pure RAW score: This table shows the performance of this lens when the file is stored in the camera in RAW format. This score approaches the intrinsic quality of the combination of lens and test camera.
Very high image quality (resolution, absence chromatic aberration)
High corner sharpness from full aperture
Very well built
Beautiful background blur/bokeh
Perfect auto focus; fast and reproducible
Visible vignetting at maximum aperture. Somewhat prone to flare.
No built-in image stabilization
The English-language press describes this lens as a "stellar performer". That may sound even more beautiful than the Dutch "top class", but both terms are accurate. A comparison of this lens with a (black) Ferrari Testarossa isn't really that crazy. Fortunately, the price of the Sony Zeiss 55 mm f/1.8 is much lower.
The introduction of 36 megapixel cameras with a full-frame sensor places extremely high demands on lenses. The Sony FE 55 mm Sonnar T* FE F1.8 ZA gives the best performance of all lenses with a focal point between 45 and 60 mm (35 mm equivalent) that we have tested to date. It is an absolute must for every owner of a Sony camera with a full-frame sensor. The image quality on virtually all fronts (resolution, distortion, chromatic aberration) is extremely high. But nothing is perfect. Vignetting, as with virtually all lenses on a full-frame sensor, is visible at maximum aperture. In night shots, you need to watch out for ghosts from a bright light source. If you really want to get the maximum resolution, then you will have to exclude movement blur. If you work with a tripod, or, if you are shooting by hand, choose a shutter speed of 1/125 second.
Author: Ivo Freriks
With Camera Review Stuff I hope to make a modest contribution to the pleasure that you get from photography. By testing cameras and lenses in the same way, evluating the results and weighing up the pros and cons, I hope to help you find the right camera or lens.