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
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.
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
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.