Featuring a back-illuminated design, the full-frame 24.2-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. The BSI design also dramatically improves data transmission speed for creating 14-bit, high-resolution stills with a native sensitivity range from ISO 100-51200, which can be further expanded to ISO 50-204800. 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 177 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.
Internal recording of UHD 4K movies is possible in multiple frame rates up to 30 fps and uses 2.4x oversampling, which renders greater detail, and full pixel readout is possible, too, for higher quality imagery with reduced moiré and aliasing. Full HD 1080p recording is also supported in frame rates up to 120 fps, and both 4K and FHD resolutions utilize the 100 Mb/s XAVC S format contained within an MP4 wrapper with 4:2:0 sampling.
The high-speed, 120 fps recording also enables 4x and 5x slow-motion 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.
Affording extensive customizable color and gamma controls, the a7 III allows users to adjust the gamma, black level, knee, color level, and more. Shooters can use the same S-Log2 Gamma Curve that is found on high end Sony Cinema cameras that squeezes up to 1300% more dynamic range into the video signal then traditional REC709, for increased post-production flexibility.
HLG (Hybrid Log-Gamma) support is available, along with the BT.2020 color space, for recording within a wide color gamut and, in addition to S-Log2, S-Log3 is also available for producing an effective 14-stop dynamic range with increased grading control in the shadow to mid-tone regions of the image.
An evolved 4D FOCUS system now employs a combination of 693 phase-detection points, which cover approximately 93% 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 a7 models, as well as improved low-light focusing.
- Lock-on AF maintains focus on moving subjects through 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 subjects’ eyes for portraits and is available in both AF-S and AF-C modes
- 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
Packed into the robust a7 III is a 5-stop effective 5-axis SteadyShot INSIDE image stabilization system that 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.
- The XGA OLED Tru-Finder EVF features a 2.36m-dot resolution and 0.78x magnification for bright, clear viewing in high detail.
- In addition to the EVF, a 3.0″ 922k-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 hand-holding.
- Weather-sealing has been employed to resist dust and moisture for reliable operation in harsh weather conditions.
- Using the NP-FZ100 battery, the a7 III has improved battery life and is now rated for approximately 710 shots per charge.
- 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.
- A USB 3.0 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.
- Built-in Wi-Fi enables the a7 III 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.