Sony Alpha 7S III (ILCE-7SM3) + Sigma 28-70mm f2.8 DG DN (C) Sony-E

Sony Alpha 7S III (ILCE-7SM3)

Almost five years after the Alpha 7S II, Sony launches its successor: the Alpha 7S III has an improved 12-megapixel sensor, shoots 4K at 120p, and is said to achieve exceptional results in low-light photography thanks to large pixels.

The sensor of the Alpha 7S III resolves 12 megapixels, as in the Alpha 7S II, but is now rear-exposed

At the heart of the new Alpha is a 12-megapixel full-frame sensor that has been improved over the Alpha 7S II. Sony now relies on a backside exposed (BSI) design, which allows more light to be captured and gives better results in low-light shooting. The maximum sensitivity is still ISO 409,600 (expandable down to ISO 40). The sensor is supported by the new BIONZ-XR processor, which is said to have eight times the processing power of the previous image processor.

Sony is also breaking new ground in terms of operation: for the first time in the Alpha 7 series, a fully movable monitor (3.0 inches, 1.44 million dots) has been installed, which now also allows touch operation of the menus. The structure of the menus has also been completely revised; among other things, only the relevant entries are available in photo and video mode for better clarity. The OLED viewfinder achieves a record resolution of 9.44 million dots and a magnification of 0.9x. The size of the image can also be reduced so that eyeglass wearers can also see the entire image.

4K with 120p
One focus of the camera is video recording. Unlike Canon on the EOS R5, Sony doesn't rely on 8K for video, but continues to rely on 4K, which is, however, said to produce the best results yet on an Alpha camera. The sensor's 12MP resolution allows full-pixel readout without pixel binning or cropping up to 4K/60p.

The recording limit at this setting is said to be one hour without overheating - the EOS R5 can only manage 30 minutes at a time at 4K/60p. Video recording is limited to this length on the Alpha 7S III in 4K/120p mode - by the way, this is also where a slight crop kicks in (1.1x).

The monitor can be swiveled, and the grip and controls have become larger - as in other cameras of the third Alpha generation.

The Alpha 7S III even records at up to 240p in Full HD. For time-lapse recordings, lower frame rates of up to 1p can also be selected in S&Q mode. Recording is done internally with a color subsampling of 4:2:2 and a color depth of 10 bit. New codecs are available for this: XAVC-S-I records single frames (All-I) at a data rate of up to 500 Mbits/s, XAVC-HS reduces the amount of data during image group compression to 200 Mbits/s thanks to H.265 compression. Via HDMI 2.1, the camera can even output 4K/60p as 16-bit raw files (ProRes Raw) to an Atomos recorder.

Of course, a logarithmic gamma profile is also available (S-Log 2/3), which is supposed to enable a dynamic range of over 15 f-stops; the sensitivity here starts at ISO 640 (extended: ISO 160). According to Sony, the rolling shutter effect has been significantly minimized.

The Alpha 7S III is equipped with a 5-axis image stabilizer in the housing, which achieves an effectiveness of 5.5 f-stops when measured according to CIPA standards; in video mode, additional digital stabilization (Active Mode) is used, which also uses a gyro sensor. The information from this gyro sensor can also be stored in the metadata of the videos to use it for digital stabilization in post-processing.

Fast autofocus and 10 fps
The hybrid autofocus covers 92% of the image sensor and uses 759 points with phase detection and 425 with contrast AF. In addition to human ones, the AF algorithms now also detect animal eyes - even at greater distances than before, according to Sony.

The AF sensitivity goes down to -6 EV. The camera shoots series at up to 10 fps. The mechanical shutter is designed for 1/8000 s. Sony uses two memory card drives for the first time in the Alpha 7S III, which can use SD cards (UHS-II) as well as the new CFexpress Type A cards. These are smaller than Type B cards and faster than SD cards. SD cards of the video classes V60 and V90 are sufficient for most video modes; only the S&Q mode with 4:2:2 color subsampling and 10-bit color depth requires CFexpress. Continuous mode also benefits from the faster cards; 1000 uncompressed raws in a row should be possible here.

A Z-battery is used for the power supply, which can be charged via USB-C and supplies power for 600 photos or 95 minutes of video. Continuous power via USB is also possible.

Sigma 28-70mm f2.8 DG DN © for Sony-E

The SIGMA 28-70mm F2.8 DG DN Contemporary redefines the standard Zoom lens for mirrorless cameras, combining outstanding optical performance and a continuous F2.8 aperture with a lightweight and compact body.

Design-wise, the 28-70mm F2.8 DG DN Contemporary is based on the 24-70mm F2.8 DG DN Art, but with a focal length range starting at 28mm. This makes the lens body much smaller and lighter, with the same excellent optical performance.

Lightweight and compact body

The slightly smaller wide-angle range of the 28-70mm F2.8 DG DN Contemporary compared to the has allowed the size of the 28-70mm body to be significantly reduced. The Contemporary product line concept balances performance and handiness.

The lens features a single, lightweight focusing element, so the AF unit can also be kept small. Together with a quiet and fast stepper motor, this provides responsive and virtually silent autofocus performance.

The 28-70mm F2.8 DG DN Contemporary weighs 470g on its own and just 890g together with the for example. At less than 1kg, such an outstandingly lightweight camera system gives photographers a tremendous amount of freedom and flexibility to realize their creative visions. It is also a perfect choice for filmmakers looking for a powerful, lightweight and easy-to-handle camera system that also works well with a gimbal and other accessories.

The genes of the Art product line

The optical design of the SIGMA 28-70mm F2.8 DG DN Contemporary is based on the 24-70mm F2.8 DG DN Art, which is known for its outstanding optical performance throughout the focal length range. The 28-70mm F2.8 DG DN Contemporary follows the core concept of the Contemporary product line: it has been designed to offer the right balance of performance and handiness. In a body light enough for everyday use, this fast standard Zoom lens thus delivers outstanding image quality that rivals lenses in the Art product line.

Outstanding build quality

Although it is commonly believed that plastic parts are more difficult to ensure processing accuracy than metal parts, no compromises have been made in the processing quality of the 28-70mm F2.8 DG DN Contemporary. One reason for this is the use of the special polycarbonate TSC (Thermally Stable Composite), which has comparable thermal shrinkage to aluminum. This reduces the differences in thermal shrinkage between metallic and non-metallic components, ensuring consistent performance even under extreme temperature fluctuations. The use of polycarbonates in the construction of Zoom and focus rings can make them appear less premium in practice. However, when these parts are carefully machined for precision and appropriately adjusted in motion by lubricants, the rings provide precise mechanics with an exceptionally high-quality feel.

Highest optical performance

The 28-70mm F2.8 DG DN Contemporary makes use of state-of-the-art technology and features a modern optical design that includes three aspherical, two FLD and two SLD elements.

Despite the overall lower number of elements than the 24-70mm F2.8 DG DN Art, the design still results in extensive correction of longitudinal chromatic aberration and sagital coma that cannot be corrected by camera. This allows users to create images that are consistently sharp from the center to the edge of the shot. In addition to the anti-ghosting design, the Super Multi-Layer and Nano-Porous coatings ensure well-controlled flare for high-contrast results even when backlit. The front lens of the lens has a water and oil repellent coating.

The everyday companion

The SIGMA 28-70mm F2.8 DG DN Contemporary offers an enhanced photographic experience for photographers with a mirrorless camera who need a fast standard Zoom lens. Its high-quality, intuitive construction makes the lens as exciting to use as the incredible images it can produce - inspiring you to realize your creative potential.

High-quality coating

An ideal lens directs incident light through all the lenses and onto the sensor. If, on the other hand, some of the light is reflected by individual lenses, not only is the light yield reduced; the reflections within the lens create ghost images and aperture spots, or they reduce the contrast. Such effects would be particularly noticeable in backlit shots.

To prevent this, the 28-70mm F2.8 DG DN Contemporary uses Super Multi-Layer Coating (SML) and Nano-Porous Coating, which reduce flare and ghosting. The result is clear, sharp, high-contrast images without distracting lens flares.