Sony E 16-70mm f/4 Zeiss Vario-Tessar T* ZA OSS SEL1670Z
Lab Test Results
June 6, 2014
by William Brawley
Fans of Sony's APS-C E-mount mirrorless cameras were surely happy to see the introduction of the Sony E 16-70mm ƒ/4 Carl Zeiss Vario-Tessar T* ZA OSS lens last year. With a very versatile 35mm-equivalent focal range of 24-105mm, a constant ƒ/4 aperture, IS and high-performance Carl Zeiss optics, the 16-70mm sub-frame lens looks to be a very useful lens for E-Mount shooters.
Part of Sony's premium lens lineup, the 16-70mm Zeiss uses "Advanced Aspherical lens" (AA lens) technology, which combines four aspherical elements with one ED glass element to control chromatic aberration as well as make for a compact and lightweight design. The lens also features Zeiss's T* coating for reduced glare and ghosting effects and Sony's Optical SteadyShot image stabilization technology.
The Sony E 16-70mm ƒ/4 Carl Zeiss Vario-Tessar T* ZA OSS lens is currently available for around $998 and ships with a bayonet-mount lens hood, soft pouch and front and rear lens caps. You can purchase this lens, or any other item, from one of our trusted affiliates: Amazon, Adorama, and B&H.
The Sony 16-70mm lens displays nice center sharpness, even wide open, and at all focal lengths, though there is a varying degree of corner softness depending on the focal length. We noticed some odd, uneven corner softness that varied with focal length and aperture. At 16mm, the upper-right corner of the frame displays a bit more softness than the other side. When stopped down a bit, the right side is slightly softer than the left (and the same can be said for other focal lens at the wider apertures, though to a slightly lesser extent). However, at 35mm, the upper-left corner is a quite a bit softer, though the same slightly skewed overall right-hand softness is present in our test graphs.
At 16mm ƒ/4, the corner softness is the most apparent, though not to a severe amount by any means. Stopping down a couple stops increases sharpness across the frame and improves corner sharpness slightly. In our lab tests, we see sharpness at all focal lengths start to decrease beginning around ƒ/11 due to diffraction limiting. At ƒ/22, the narrowest aperture, diffraction limiting softness is apparent at all focal lengths, but the most noticeable degree is at 16mm. However, in real-world shooting, and even with our Still Life test shots, the lens performed admirably, even wide open with a nice amount of sharpness overall.
Despite the "Advanced Aspherical lens" design to help reduce chromatic aberration, CA is still quite apparent, particularly at 16mm and 70mm in the corners. It's not a deal-breaker, as CA isn't that extreme, but it is noticeable with bright purple-ish fringing appearing on high contrast edges out near the corners when shooting wide open, and to a slightly lesser extent when stopped down. Center CA performance is quite good, both wide open and stopped down and at all focal lengths, based on our test chart images.
All the focal lengths display some chromatic aberration to some degree, with 16mm-24mm displaying slightly more in the corners compared to the other focal lengths. CA in the center of the frame, however, is excellent at all focal lengths both wide open and stopped down.
There is a strange anomaly with corner CA at 35mm, which we believe is correlated to the uneven corner softness we saw at this focal length. In the upper left corner at ƒ/4, we can see noticeable CA, but also with some odd haziness or blurriness as well. Stopping down a bit, however, clears up this haze/blur and a lot of the CA.
It should also be noted that depending on the Sony camera you use, it could be applying some in-camera processing. In the case of our Sony NEX-7 test camera, there is CA lens correction set to "Auto" by default. We shoot all of our DxO RAW images for our test graphs with any corrections disabled, but our Still Life and VFA test photos at default camera settings.
Uncorrected, the Sony 16-70mm clearly displays vignetting, especially at 16mm. At ƒ/4, it's a bit under a full 1EV of light falloff, but drops to around 0.5EV at ƒ/8. We saw a slight increase in vignetting again past ƒ/8, but still under 0.75EVs.
The other focal lengths show noticeably less vignetting, though it's still present, especially at ƒ/4. Interestingly, 24mm and 70mm display the next highest amounts of vignetting with around 0.5EVs at ƒ/4 with 24mm dropping to just over 0.25EVs from ƒ/5.6 onwards. 70mm drops to around 0.25EVs at ƒ/5.6, but then decreases significantly at the smaller apertures. Vignetting at 35mm and 50mm are quite similar with maximum vignetting at ƒ/4 of only around 0.25EVs with it reducing further as you stop down.
Again, like CA, the Sony cameras may have in-camera shading correction enabled by default.
As expected with a wide-angle zoom lens, the Sony 16-70mm shows some visible barrel distortion at 16mm, though on average it's only around +0.5% (and the corners are a little higher but still under 1%). However, when zoomed to 24mm and longer, the lens exhibits some pincushion distortion (though there is still a bit of barrel distortion on average). As with CA and vignetting, Sony cameras may have in-camera distortion correction enabled by default.
Fans of speedy autofocus will be happy with the Sony 16-70mm lens. Changes in focus are super quick and even racking from minimum focus distance to infinity takes well under one second. Even in dimmer lighting, AF felt fast and accurate even on our contrast-detect-only test body, the Sony NEX-7. On newer cameras like the A6000 with hybrid phase-detect and contrast-detect, the AF performance may improve even more.
Of course there's also manual focus, but unlike a DSLR lens, there's no AF/MF switch on the lens itself nor is there any form of focus distance marking -- it's a focus-by-wire system. Those are controlled via the camera body. The small, 3/8th-inch wide focus ring rotates very smoothly, and the thin plastic ribbing is subtle but provides enough friction to use the side of your finger to adjust focus as you hold the lens.
This lens has a maximum magnification ratio of 0.23x (1:4.3) and a minimum close-focusing distance of around 0.35m (1.15 ft.), which doesn't make it a great lens for macro photography.
Build Quality and Handling
In typical Sony/Zeiss minimalist styling, the 16-70mm is a sleek, compact lens with a mixture of metal and strong polycarbonate plastic construction, with a near-matte, all-black finish. Apart from small Sony and Zeiss branding logos, the rest of the exterior is pretty sparse with only simple focal length markings for 16, 24, 35, 50 and 70mm. As mentioned in the focusing section, there's no AF/MF switch or focus distance markings or DOF scale.
In terms of optical construction, the Sony 16-70mm lens features 16 elements in 12 groups, including a combined 4 aspherical elements and 1 ED glass element configuration that Sony calls Advanced Aspherical lens technology. This "AA lens" tech helps cut down on the size and weight of the lens. The constant ƒ/4 aperture helps keep the ISO level down with zooming and also helps with better subject isolation and bokeh (compared to your typical kit zoom lenses that usually stop down to ƒ/5.6 at the tele end). The constant aperture is also great for video shooters, as they can maintain the same exposure settings while zooming. The 7-bladed circular aperture also helps with smoother background blur.
The zoom ring is very smooth to rotate with just enough resistance to avoid any sort of lens creep, yet light enough that two fingers is all it takes to rotate it. The focus ring, as on most focus-by-wire lenses, is super smooth to rotate without any hard stops on either end.
The focus and zoom rings sit adjacent to each other toward the front of the lens making for a comfortable, balanced hand-holding spot. Overall, the lens feels great in the hand and very well balanced on Sony's NEX mirrorless cameras -- in both wide and tele positions. The lens does protrude out quite a bit -- approximately three inches plus another inch or so for the lens hood. And when zooming, the lens extends out another 1.5 inches. Nevertheless, the lens is lightweight, versatile and shouldn't be a problem to carry around if you're out and about and want a one-lens solution.
The Sony E 16-70mm ƒ/4 Carl Zeiss Vario-Tessar T* ZA OSS lens is quite a unique offering for E-mount shooters as there aren't really any other options for a lightweight, relatively compact zoom lens with a constant aperture. There are are some alternatives, however, that share some similarities or features.
First up is the standard APS-C E-mount kit zoom lens, the Sony E 16-50mm ƒ/3.5-5.6 PZ OSS. This inexpensive lens is extremely compact with an almost pancake style when completely retracted (~30cm thick). However you lose a bit of telephoto capability with the maximum focal length of only 50mm, as well as the nice constant ƒ/4 aperture. The Sony E 16-50mm is also noticeably softer and displays significantly more vignetting and distortion. CA control is quite good, however.
A similarly priced inexpensive alternative is the Sony E 18-55mm ƒ/3.5-5.6 OSS, which is the older kit lens for various NEX models. Though not in the same pancake-ish size as the 16-50mm lens, the 18-55mm is still smaller than the Sony 16-70mm Zeiss. Apart from the price and size, however, the Zeiss trumps in nearly every area: sharpness, less distortion and less CA.
If you're looking for a bit more versatility, the Sony E 18-105mm ƒ/4 G PZ OSS might be a viable alternative, however, it's quite a bit larger than the 16-70mm Zeiss. Those who don't mind sacrificing a couple millimeters on the wide end for significantly more zoom on the telephoto end, might take an interest in the Sony 18-105mm. While we haven't tested this lens yet, it doesn't carry the Zeiss name, however with 2 ED glass elements, 3 aspherical elements as well as Optical SteadyShot technology, the Sony 18-105mm could be a promising option. It's also about $400 less than the 16-70mm at around $598.
There's also another possible alternative, though it might be a bit of a stretch. If you're an E-mount shooter looking for a zoom lens and are considering upgrading to one of Sony's full-frame E-mount cameras in the future, perhaps the Sony FE 24-70mm ƒ/4 ZA OSS Carl Zeiss Vario-Tessar T* can be viewed as an alternative. As the Sony 16-70mm ƒ/4 Zeiss lens's full-frame sibling, this high-end zoom lens shares many of the same features. The focal length range of the Sony 24-70mm won't be as versatile on APS-C E-mount cameras, as your field of view is cropped, so you lose some wide-angle usefulness. Also, we found the Sony 24-70mm didn't meet our expectations on sharpness, at least on the full-frame Sony A7R, considering the almost $1200 price tag, and while CA performance is good, distortion and vignetting are problematic. Of course, the issues with corner softness and vignetting that we saw on a full-frame camera will be lessened when used on an APS-C camera.
For Sony shooters using APS-C E-mount cameras, the Sony E 16-70mm ƒ/4 Carl Zeiss Vario-Tessar T* ZA OSS lens is a very versatile, lightweight, well-built lens with good image quality. The images are quite sharp, even wide open, and the autofocus performance is excellent.
While Sony cameras, by default, include in-camera chromatic aberration, vignetting and distortion correction, we did see some CA in the corners, noticeable (though not severe) vignetting, and some distortion with uncorrected RAW images. In real-world shooting, however, the results are quite nice -- sharp photos, particularly in the center, and other factors like CA, vignetting and distortion are easily correctable in post-processing.
With a compact size and lightweight design, the Sony 16-70mm Zeiss is an excellent walkaround lens, although with a price tag around $1000, it's quite an expensive one. For those times when you want a versatile, single-lens solution for general photography, travel, landscapes and portraits, the Sony 16-70mm is a good choice.
The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.
As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.
Sony E 16-70mm f/4 Zeiss Vario-Tessar T* ZA OSS SEL1670Z
Sony E 16-70mm f/4 Zeiss Vario-Tessar T* ZA OSS SEL1670Z User Reviews
9 out of 10 points and recommended by gmnguyen (1 reviews)sharp, good contrastN/A
The Sony E 16-70mm F4 is an excellent lens. It is sharp and high contrast at ALL focal length and ALL aperture. Usually, a zoom lens tend to be soft at the tele end and wide open. The Sony 16-70 is very sharp at 70mm F4. I can do nice portrait shots at 70mm f/4 but I have to set the 18-55 kit lens to F8 at 55mm because the kit lens is very soft at 55mm F5.6. I cannot get nice bokeh with the kit lens. The 16mm is very nice, too. In real life, the contrast is always on high level.reviewed August 20th, 2014
Is it expensive at $1000? No. The Olympus 12-40 f/2.8 is in the same price range. The M43 f/2.8 gives similar bokeh as the f/4 on APS-C sensor. The DSLR Nikon 16-85 f/3.5-5.6 is $700 but it is not constant f/4.