Featuring a back-illuminated design, the full-frame 42.4-megapixel Exmor R CMOS sensor works with the BIONZ X image processor to offer high-resolution stills and video while minimizing noise and improving speed. This sensor structure works with gapless on-chip lens design and an anti-reflection coating, as well as eliminating the optical low-pass filter, to improve light collection and enhance detail. Also, the copper wiring layer dramatically improves data transmission speed for creating 14-bit, high-resolution 42.4-megapixel stills with a native sensitivity range from ISO 100-32000, which can be further expanded to ISO 50-102400. Also, it enables internal UHD 4K video recording with a wide dynamic range using the full width of the full-frame sensor. The BIONZ X processor also works in conjunction with a high-speed front-end LSI to realize faster processing times along with the ability to capture an impressive 15-stop dynamic range at low sensitivity values.
The sensor and processor combination also avails fast continuous shooting at up to 10 fps at full resolution, for up to 76 consecutive frames, and with full-time AF/AE when working with either a mechanical shutter or an electronic shutter. If shooting in live view mode, a continuous shooting rate of up to 8 fps is also possible.
An evolved 4D FOCUS system now employs a combination of 399 phase-detection points, which cover approximately 68% of the frame, along with 425 contrast-detection areas for reliable and quick autofocus and subject tracking performance. This Fast Hybrid AF System now achieves twice the focusing speed and more reliable tracking compared to previous a7R models, as well as improved low-light focusing response down to -3 EV.
- Lock-on AF maintains focus on moving subjects throughout the use of a configurable frame that is set over the desired moving subject
- Expand Flexible Spot employs neighboring focus points to retain focus on moving subjects even if the originally selected point loses focus
- Eye AF can be used to base focus on recognized human subjects’ eyes for portraits and is available in both AF-S and AF-C modes, for both stills and video. Eye AF can be used when photographing animal subjects, too, with any focusing mode when shooting stills
- Focus Magnifier function can be used for critical focus when homing in on minute subject details
- Rear touchscreen can also be used for Touch Focus control, and a Touchpad Focus Control mode lets you use the rear screen intuitively while keeping your eye to the viewfinder
- For more personalized control over focus, and benefitting working in either vertical or horizontal shooting orientation, the AF area can be switched in orientation to better suit your subject matter
- AF tracking sensitivity can also be customized in five steps to match how a subject is moving
- Frequently used focus point settings can be memorized and recalled with a custom button for faster switching between focus settings
The a7R IIIA incorporates an enhanced 5.5-stop effective 5-axis SteadyShot INSIDE image stabilization system, which compensates for five different types of camera shake encountered during handheld shooting of stills and video. This allows users to confidently use any lens, even adapted lenses, for critical imaging without encountering blur from camera shake.
For long focal lengths, the system will correct for pitch and yaw adjustments. Macro and high-magnification imagery, on the other hand, will benefit from the inclusion of horizontal and vertical shift compensation. All shooting styles will get usage out of the roll compensation. All 5 axes of stabilization will function at all times, even when used with third-party lenses and adapters or lenses with built-in optical stabilization.
- Internal recording of UHD 4K video is possible in multiple frame rates up to 30 fps using the full width of the sensor with 8-bit 4:2:0 color sampling using the 100Mbps XAVC S codec.
- Oversampled 4K recording is also possible, which uses a 5K capture area with a Super 35 crop for greater detail. This full pixel readout is void of pixel binning for higher quality imagery with reduced moiré and aliasing.
- Full HD 1080p recording is also supported in frame rates up to 120 fps. The high-speed, 120 fps recording also enables 4x and 5x Slow& Quick Motion (S&Q) movie recording with the frame rate set to either 30p or 24p.
- In addition to high-resolution internal recording, uncompressed HDMI output also enables the use of an optional external recorder for clean 4K recording with 4:2:2 sampling.
- 4K video recording also avails the ability to produce 8MP stills during playback by taking a frame grab from a movie and storing it as a separate file.
- HLG (Hybrid Log-Gamma) support permits recording within a wide color gamut for producing HDR-ready content directly from the camera.
- S-Log3 is also available for producing a 14+-stop dynamic range with increased grading control in the shadow to mid-tone regions of the image.
- An updated Quad-VGA OLED Tru-Finder EVF is featured and has a 3.69m-dot resolution for bright, clear viewing in high detail. Both Standard and High-quality settings can be used, depending on the shooting situation, in order to optimize the viewing experience.
- In addition to the EVF, a 3.0″ 2.36m-dot rear LCD is also available, which has a touch panel design for intuitive operation and focusing control. The screen also tilts upward 107° and downward 41° to benefit working from high and low angles.
- Magnesium alloy chassis assures rigidity, durability, and stability while remaining lightweight. The lens mount has also been improved to better support heavy lenses and the grip rigidity has been improved for more comfortable handholding.
- A durable shutter unit incorporates a coreless motor and brake system that reduces vibrations to better control shutter shock as well as extend its rated lifespan to approximately 500,000 actuations.
- Weather-sealing has been employed to resist dust and moisture for reliable operation in harsh weather conditions.
- Using the same NP-FZ100 battery as the a9, the a7R IIIA has improved battery life and is now rated for approximately 530 shots per charge with the EVF or 640 shots with the rear LCD.
- Dual SD memory card slots allow for flexible file saving and handling and can be configured to partition raw and JPEG files or can be used for overflow recording. One of the card slots is rated to support UHS-II memory cards.
- Integrated PC sync terminal for wired flash sync with strobe packs or wireless radio remotes.
- A USB 3.2 Gen 1 Type-C port has been added, in addition to a micro-USB port, for faster, more reliable tethering support. The USB Type-C connection allows the camera to be charged from the host power source while connected.
- The a7R IIIA features a 3.5mm microphone input jack for compatibility with external microphones. And for users needing more, the camera is also compatible with the Sony XLR-K2M XLR Adapter for recording professional balanced XLR audio signals with phantom power and adjustable mic/line inputs. For monitoring audio, a 3.5mm headphone jack is available as well as real time audio levels for a visual reference.
- Built-in Wi-Fi enables the a7R IIIA to instantly share imagery to mobile devices for direct sharing online to social networking, via email, and to cloud storage sites. NFC (Near Field Communication) is also supported, which allows for one-touch connection between the camera and compatible mobile devices; no complex set-up is required. Once connected, the linked mobile device can also display a live view image on its screen and remotely control the camera’s shutter.
- Bluetooth connectivity allows for location data acquisition.