Sony's breakthrough 42.4MP full-frame mirrorless — first with BSI sensor, 5-axis IBIS, and 4K video.
The Sony Alpha A7R II was released in 2015 as the second-generation A7R, adding 5-axis in-body stabilisation (4.5 stops CIPA) to the high-resolution full-frame mirrorless concept and upgrading to a 42.4MP BSI (back-illuminated) full-frame sensor. 4K/30fps full-pixel readout with oversampling. 5fps burst. NP-FW50 battery (modest ~290-340 shots). At approximately 625g with battery.
42.4MP full-frame BSI Exmor R CMOS sensor. 5-axis IBIS rated 4.5 stops. 5fps burst with AF/AE tracking. 4K/30fps full pixel readout (oversampled from 6K-equivalent). Real-Time Eye AF (early iteration). NP-FW50 battery (~290 shots EVF / 340 shots LCD — modest capacity). Approximately 625g with battery. Dual UHS-I SD card slots.
The A7R II's IBIS addition over the A7R was transformational: the original A7R had no stabilisation at all, limiting it for handheld non-tripod work. The 5-axis IBIS at 42.4MP provides sharp images at lower shutter speeds that unscaled resolution demands. The BSI sensor provided improved low-light performance over the front-illuminated A7R sensor. The NP-FW50 battery weakness (~290 shots) was widely noted as a limitation.
On the used market the Sony A7R II is affordable as a vintage 42MP Sony FE mirrorless. Condition checks: NP-FW50 battery health (shared with A6000 series — small battery, modest capacity), IBIS operation, dual SD slot contacts. Compatible with all Sony FE-mount lenses.