Sony Alpha 7S II Review: Introduction
At a glance:
- 12.2MP full-frame Exmor CMOS sensor
- ISO 100-102,400 (standard) 50-409,600 (expanded)
- 169 contrast-detection AF points
- 5-axis optical image stabilisation
- 4K video (100Mbps)
- £2,500 (body only)
When Sony launched the Alpha 7 and Alpha 7R two years ago, the manufacturer was looking to target two different types of photographer. While the Alpha 7 was out to appeal to enthusiasts looking for a full-frame camera with an ‘all-round’ level of performance, the Alpha 7R was aimed at landscape and studio photographers who wanted to record the highest level of detail from Sony’s 36.4-million-pixel full-frame sensor.
Not content with two models in the Alpha 7 series, Sony identified demand for a third Alpha 7-series model that would satisfy the needs of videographers who wanted to record 4K video – while also fulfilling still photographers’ requests for a camera that could perform exceptionally well in low light. The Alpha 7S received high acclaim from those it was designed for. However, there were a few characteristics that could be improved – its autofocus system and handling being two examples. With the Alpha 7 and Alpha 7R now in their second generation, it was only a matter of time before Sony focused its attention on the Alpha 7S again in an attempt to make it even better. On first glance you’ll notice that the Alpha 7S II is built around an improved body that’s identical to the Alpha 7 II and Alpha 7R II, but there’s plenty more to comment on besides.
Sony Alpha 7S II Review: Features
Unlike the Alpha 7R II, which improved on its predecessor by debuting the world’s first back-illuminated full-frame chip with a 42.2-million-pixel resolution, the Alpha 7S II employs the same 12.2-million-pixel full-frame Exmor CMOS sensor found in the Alpha 7S. Although this pixel count seems low when compared to other full-frame cameras on the market, it has a significant advantage over sensors with a higher pixel density in that each photosite (or pixel) on the chip is larger. The combination of a large full-frame imaging sensor and larger pixels equates to superior light-gathering capabilities and unprecedented low-light performance – something that
is reflected in the Alpha 7S II’s sensitivity range.
Like the original Alpha 7S, the Alpha 7S II has a sensitivity of ISO 100-102,400, with the option to expand it further to an astonishing ISO 50-409,600. The sensor teams up with Sony’s Bionz X image processor and there’s also the option to shoot in the 14-bit uncompressed raw format (also available to Alpha 7R II users via a firmware update). This is alleged to offer improved quality of tonal gradation and eliminate any compression artefacts.
In an effort to improve focusing, Sony has introduced what it calls a Fast Intelligent AF system. This shouldn’t be confused with the Fast Hybrid AF system that features on the Alpha 7 II and 7R II. Instead of using on-sensor phase detection, the Alpha 7S II relies on contrast detection to acquire focus and provides 169 AF points in total. Each of the nine central points is divided into 16 segments to provide a higher concentration of AF points in the centre. With an f/2 lens attached, Sony claims it’s possible to focus when light levels drop to -4EV.
Another feature that I expected to make its way into the Alpha 7S II is the 5-axis in-body image-stabilisation system that we’ve seen before on the Alpha 7 II and 7R II. The system compensates for the familiar pitch and yaw movements, but also corrects for movements of the camera vertically and sideways. The fifth axis corresponds to the rotational correction around the lens axis, which is crucial for video recording and ensuring high-resolution handheld images remain at their sharpest. The advantage of fitting this image-stabilisation system to the Alpha 7S II is that it allows users to dial in a shutter speed 4.5 stops slower than would otherwise be possible. In addition, it also opens up the possibility of shooting stabilised images no matter which lens is attached – whether it be a zoom with optical stabilisation built in, or a prime lens without.
There’s more on offer, too. The Alpha 7S II features a newly designed shutter that’s tested to 500,000 cycles and reduces mechanical front and rear-curtain vibration. The electronic front-curtain shutter is enabled via the main menu and above it you’ll find the camera’s silent shooting mode. Switching this on disengages the electronic front-curtain shutter and engages the Alpha 7S II’s fully electronic shutter. With silent mode deployed it’s possible to shoot in silence without disturbing a subject. However, unlike some cameras with an electronic
shutter, it’s not possible to push the shutter speed past its 1/8,000sec maximum.
Another feature that’s been updated is the viewfinder. The Alpha 7S II inherits the same EVF that impressed us on the Alpha 7R II, and although its 2.36-million-dot resolution suggests it’s the same as that on the Alpha 7S, it has a larger 0.78x magnification.
Below the EVF there’s an improvement in screen quality, too. The 3in, 1.23-million-dot display advances on the 3in, 921,000-dot display of old, offering 107° of adjustment up and 41° down when it’s tilted. To keep the sensor free of imperfections, an anti-dust mechanism helps to dislodge any particles that may adhere to the sensor. There’s Wi-Fi connectivity and NFC for instant pairing to compatible devices, and the micro USB interface at the side makes it possible to keep the battery topped up while you’re shooting and conveniently recharge it when you’re on the move. It’s good to see Sony boxing its latest Alpha 7-series cameras with a pair of NP-FW50 batteries and each of these lasts for around 300 shots.