This is far from a novelty, but the Sony FE 28-70mm f/3.5-5.6 OSS is still offered in kit with several hybrids such as the A7 III. This is what leads you to regularly ask us for it’s review and ground test… and finally its here.
- Sony E Mount.
- Maximum Covered Format: 24×36.
- Actual Focal Length: 28-70 mm.
- Maximum Opening: f/3.5-5.6.
- Minimum Opening: f/36.
- Reproduction Ratio: 0.19x.
Main Characteristics of Sony FE 28-70mm F/3.5-5.6 OSS
This is the cheapest 24x36 sensor hybrid zoom lens in the Sony catalog. But it is essentially in kit that the FE 28-70 mm f/3.5-5.6 OSS is proposed in order to display case + lens formulas at a reasonable price. The lens is proposed with A7, A7 II and A7 III. Since the Sony FE mount is common to all hybrids of the brand, the lens can also be combined with an A6400 or a previous generation device with which it will behave like a 42-105 mm.
Its focal range is less wide than that of the most common trans-standards and only starts at 28 mm and ends at 70 mm. its maximum aperture is slippery and never very bright, since it extends from f/3.5 to f/5.6 from one end of the focal range to the other.
Its manufacture is based on the presence of nine optical elements divided into eight groups including three aspheric lenses and one in ED glass. The lens is equipped with a steady shot optical stabilization system. Its minimum focus distance is 30 cm at the wide angle and 45 cm at the telephoto lens, which allows it to achieve a maximum magnification ratio of 0.19 x. The lens can receive filters 55 mm in diameter. It measures 72.5 x 83 mm and weighs 295 G. it comes with its sun visor.
The moderate cost of the lens does not allow us to enjoy the best manufacture of Sony lenses. The FE 28-70 mm f/3.5-5.6 OSS doesn't even weigh 300 gm, but its assembly is accurate and Sony says its design is dust and moisture resistant. The transition from one end of the focal range to the other results in an elongation of the lens.
The two rubberized adjustment rings provide a good grip. The widest is reserved for zoom adjustment. It has good friction while allowing a quick passage from 28 to 70 mm in less than a quarter of a turn. Right next to it, the focus ring is narrower. It also has a good friction that allows a good precision of movement. However, it does not have a stop.
The lens also does not have a window displaying a distance scale. This is replaced by a display in the device in manual mode. We can then check that we turn the ring in the right direction and that we are at the minimum distance or infinity. But for this, it is mandatory to go through the settings of the case, because the lens does not have a selector switch to quickly switch from AF mode to MF. The stabilization system cannot be deactivated either.
The lens comes with a Corolla sun visor that does not have a locking mechanism but still holds very well in place.
Ground Test of Sony FE 28-70mm
This trans-standard is designed to offer great versatility to its users, allowing them to indulge in both landscape and portrait photography. However, its shortest focal length only starts at 28 mm, offering a 75° angle of field. On the ground, this makes a big difference to the Zeiss Vario-Tessar FE 24-70 mm f/4 za OSS that is also found in kit with its 84° angle of field at the shortest focal length.
Its minimum focus distance of 30 cm at the wide angle and 45 cm at the telephoto lens is a bit long for close-up subjects and does not give such versatility to the lens. As for its slippery opening, it is a handicap. Not because it is not constant throughout the field, but more because it is never very bright. f/3.5 at wide-angle and f/5.6 at telephoto does not leave much freedom to create nice bokeh effects and requires to rise in sensitivity as soon as the light is not intense.
Note that vignetting is relatively present at all focal lengths and is particularly evident when a point source is in the background. We can see clearly from our laboratory tests the truncated circles in the corners. An onion-ring phenomenon is also clearly visible.
On the other hand, distortion is very well controlled. It is very slightly present with a wide-angle barrel manifestation and then disappears completely.
It is difficult to judge the effectiveness of the stabilization since it is not possible to disable it on the lens and the A7 III with which we conducted our field tests also has a sensor stabilization system. This criterion is therefore not decisive in choosing a lens for this range of devices.
As for the auto-focus, without being hyper-fast, it gave us rather satisfaction, until it became very noisy. Our test lens obviously encountered a technical problem that does not allow us to judge its quality, but perhaps rather the reliability of the lens. This is unfortunately the fears that we still have with these entry-level lenses: that the manufacture is not homogeneous from one product to another and that it happens to come across a defective model, which seems to be the case with the auto-focus engine of our goal.
The notion of pique is quite delicate to deal with. This is what can be equated to the "sensation of sharpness" or the "accuracy" observed on an image. It can be very different from one lens to another, from one focal point to another and from one aperture to another. It can also vary between the center and edges of the image.
We tested the lens in the lab with a Sony A7R II, 24 x 36 mm sensor of 42 Mpx. The A7R II has a definition of 7952 x 5304 px. Each pixel thus measures 4.54 µm sideways. The results were exploited using the Imatest software — you will have already noted that the field tests were carried out with a Sony A7R III.
The resolution of the lens is quite suitable in the center of the image at 28, 35 and 50 mm focal lengths with virtually constant results from the full aperture. But things spoil at 70 mm and you have to close the diaphragm at f/11 to start having satisfactory results.
At this focal point, the lens is rather homogeneous in its mediocrity, but at weaker focal points, there is a very clear withdrawal of the edges of the image at virtually all openings. The resolution practically does not increase, and the fine details of the image are never correctly rendered.
These results measured with Imatest are confirmed by the photos of our test scene. The details chosen on the edges of the image are poorly transcribed. We can also see traces of very unsightly chromatic aberrations, also visible on our field photos.
• Good grip.
• Dim light.
• Lack of homogeneity.
• Traces of chromatic aberrations.
• Vignetting marked.
If it allows Sony to offer low-cost kits, the FE 28-70 mm f/3.5-5.6 OSS is a lens that really does not do justice to the quality of the cases. Its optical qualities are very poor at the edges of the image, its focal range a little weak and its maximum aperture slippery dim. If you want to enjoy your case, prefer another kit zoom such as the FE 24-105 mm f/4 G OSS or opt for a bare case purchase by adding a bright fixed focus such as the FE 50 mm f/1.8.