The Sony a7RIII is a great upgrade to our previous, very beloved camera, the Sony a7RII.
- Back-illuminated 42mp full-frame sensor.
- Silent shutter mode and electronic front curtain shutter.
- Blackout-free shooting in silent shutter mode, with vibration-free electronic shutter.
- High-speed continuous shooting at up to 10fps.
- SteadyShot 5-axis in-body stabilization with up to 5.5-stop shutter speed advantage.
- Mechanical shutter ISO ISO 100-32000, expandable to ISO 50-102400.
- 399 points (phase-detection AF), 425 points (contrast-detection AF), rated to -3 EV sensitivity.
- Continuous eye autofocus, which automatically detects and tracks an eye of a moving person, even if the face is turned at an angle or partially obscured.
- 4k video recording at 30fps and full HD video recording at 120fps, with Super 35mm mode and clean HDMI output.
- Electronic viewfinder with 3686k dots, 0.78x magnification, 120fps, and 100% coverage.
- Articulating touch-enabled LCD screen that tilts both up and down.
- Joystick on the body to quickly change autofocus point.
- Minimum shutter speed for auto ISO, with options to change how the camera responds to changes in lighting.
- 1/8000th sec. mechanical shutter, 1/250th sec. flash sync speed.
- Small and compact body size for its class of camera, despite being a bit larger and weighing more than other Sony FF mirrorless cameras.
- Dual card slots and USB-3 Type C port.
As we have extensively used both the Sony a7RII and the Sony a9 cameras, the a7RIII is very familiar and easy to set up for us. From the outside it does not look very different from the other bodies in the Sony full-frame mirrorless lineup.
The a7RIII addresses almost all of the issues and concerns we had about the a7RII, such as lack of dual card slots, no touch screen, no USB-3 and low battery life.
The speed of operation such as reviewing photos and zooming in to check focus is much improved over the a7RII. However, it is still not as fast as the a9, which is the most responsive camera we’ve used.
The speed and reliability of continuous eye autofocus has been greatly improved in the a7RIII. It is not quite on par with the a9, especially in low light, but compared to the a7RII it is able to find the near eye in a much greater variety of situations. For example, it was able to find a child’s eye in the following backlit scene with their faces turned a bit away from the camera:
In good light the a7RIII is able to catch action shots relatively well, even when using relatively slow autofocusing lenses. But in low light, the a7RIII can lag behind the a9 for action shots. The results are acceptable, but often misses critical focus when compared to the a9’s ability to nail focus in low light. Also, whereas the a9 can perform continuous autofocus (AF-C) using PDAF points at f8 to f11, the a7RIII will hunt at apertures above f8.
Silent shutter mode also has a slight delay compared to normal shutter, especially in continuous shooting. It can still capture some good shots as long as there is not a lot of risk of rolling shutter.
Just like its predecessor, the a7RIII produces superb image quality, detail, color, and dynamic range with its backside-illuminated 42 megapixel sensor.
There is very little noise at high ISO, especially when downsampled to lower resolution for screen viewing.
At base ISO 100, the sensor delivers great dynamic range and color fidelity. The RAW files from the a7RIII feel very malleable to post-processing.
The a7RIII can output full 14 stops of dynamic range in silent shutter mode with the electronic shutter. This means that there is no loss in image quality, as long as the subject is not moving rapidly. The new pixel shift mode in the a7RIII makes use of this silent shutter capability, which makes sure there are no vibrations. Pixel shift increases detail and resolution by combining 4 captures that are shifted by just 1 pixel, but it requires a motionless subject.
The detail difference between the a7RIII and the a9 is noticeable when viewing side-by-side, but not very noticeable without a direct comparison. Unless cropping significantly or printing large is desired, 42mp is a luxury rather than a necessity.
The third generation of Sony mirrorless cameras is awesome. We love the longer battery life, better autofocus performance, increased buffer size, faster speed of operations, improved ergonomics, and inclusion of joystick dial and dual card slots. There are still some aspects that could be further refined, like fully articulating LCD screen and stronger weather sealing, though these might add size and bulk to the bodies, which do weigh more than the previous generation.
If we only shot landscapes and slow-moving subjects, we would probably not feel the need to upgrade to the a7RIII. But after using the a9 to take photos of constantly moving kids, we wanted a body that would be able to keep up with the action. The a7RIII and the a9 together feel like a great pair that can do just about anything we want photographically. In truth, either one is very capable of doing just about anything photographically.