Sony A7R II sensor review: New high water mark in sensor dynamicsBy Kevin Carter - Thursday August 27 2015 Sensor Review
Building on the success of the full-frame 36-Mpix Sony A7R, the recently announced update to that model looks to be one of the most promising cameras of the year. Along with a slight increase in pixel count over the original, the sensor in the 42-Mpix A7R II offers BSI architecture and on-chip PDAF with 399 points. Read on to find out how well this new sensor performs.
Specifications and Features
With the original Sony A7R mirrorless camera offering a related sensor and therefore similar performance to the much larger and heavier Nikon D810 SLR, it’s perhaps unsurprising that the update to that model, the Sony A7R II, is one of the most talked-about models of the year. Although the body is a little bigger (and more durable) than its predecessor, the A7R II has potentially a lot more to offer.
Along with an increase in pixel count to 42-Mpix, the full-frame sensor is the first of its kind to feature backside illuminated (BSI) architecture for improved low-light performance. As a consequence, the larger pixels not only gather more light, but in theory they also reduce the effects of shading and color shifts at the periphery of the frame. This is particularly so when mounting lenses that project highly oblique light rays (such as short focal length rangefinder lenses).
More room for larger pixels and more electronics means Sony has boosted the number of dedicated on-chip PDAF pixels. It now features 399 phase-detect points (plus 25 contrast-detect points) that should aid AF performance, particularly with A-mount lenses when used with the relevant adapter. In addition, the sensor is now mounted on a stabilized platform and offers compensation for vibration along 5 axes at up to 4.5 stops (CIPA standard). High-speed architecture and a powerful Bionz X-type processor allows UHD 4K (3840x 2160) video capture in Super 35mm crop or full-frame mode at 30/25/24 fps, and at high bit-rates up to 100Mb/s.
Although we’re principally concerned with the sensor dynamics here at DxOMark — and the sensor spec is impressive — the camera features an improved shutter design with greater durability and lower vibration. It also features an electronic front-curtain feature to further reduce the effects of vibration, as well as a fully-electronic silent shutter option. Also upgraded is the built-in finder. It’s now a 2.36M-dot OLED type with a 0.78x magnification. At the rear, the A7R II has new 3.0” 1.3M-dot tilting LCD with increased brightness and more accurate color using RGBW pixel layout. Both display zebra- and focus-peaking, plus there’s a 3.5mm microphone jack and same-size headphone socket with a real-time levels display. Finally, built-in WiFi connectivity with NFC allows live view and camera control with mobile devices.
The Sony A7R II measures 5.0 x 3.8 x 2.4” / 126.9 x 95.7 x 60.3mm and weighs 22.05 oz / 625g. It is available now at around $3,200 (USD).
- 42-Mpix full-frame R Exmor R BSI CMOS sensor
- Built-in 5-axis stabilization platform
- 399 on-chip phase-detect points
- ISO102,400 and EFC (electronic front curtain)
- Reduced vibration shutter
- Bionz X image processor
- Continuous shooting up to 5 fps.
- 2.36M-dot OLED EVF
- 3.0-inch 1.3M-dot tilting LCD
- UHD 4K video at 30/25/24 fps, HD up to 60 fps
- Built-in WiFi with NFC