Sony's third-generation high-resolution mirrorless with 42.4MP and improved AF.
The Sony Alpha A7R III was announced in October 2017 as the third-generation high-resolution A7R-series body, combining the 42.4MP BSI Exmor R CMOS sensor of the A7R II with updated processing, dual SD UHS-II card slots, and the NP-FZ100 battery — replacing the NP-FW50 that had defined the first two A7R generations and significantly improving battery life. 10fps continuous burst was a major advance over the A7R II's 5fps. IBIS at approximately 5.5 stops is built in.
The 42.4MP full-frame BSI Exmor R CMOS sensor pairs with the BIONZ X processor. The AF system uses 399 phase-detection points supplemented by 425 contrast-detection points. Burst shooting runs at 10fps with continuous AF. 4K video records at up to 30fps from the full sensor via oversampled pixel readout; S-Log2 and S-Log3 are available. 5-axis IBIS provides approximately 5.5 stops of compensation. Battery life approximately 650 shots using the NP-FZ100, body weight approximately 650g with battery and card, dual SD UHS-II card slots.
The A7R III's 10fps burst at 42.4MP was the resolution-speed combination that established it as the professional hybrid standard for the A7R line — the A7R II's 5fps had limited action and wildlife use of the high-resolution body. The NP-FZ100 battery at 650 shots addressed the chronic limitation of the NP-FW50 era. Dual SD UHS-II slots provided professional redundancy for the first time in the A7R series. The 42.4MP resolution enables significant crop headroom for wildlife and sports as well as large-format output.
On the used market the A7R III is available at substantially reduced prices compared to the A7R IV and V. Condition checks: IBIS operation, both SD slot contacts, NP-FZ100 battery health, and shutter count — rated 500,000 actuations. The A7R IV (2019) added 61MP and improved real-time tracking at a higher price. The NP-FZ100 is the standard Sony full-frame mirrorless battery. Compatible with all Sony FE-mount full-frame and APS-C E-mount lenses.