The 24-megapixel A7 was already the world's smallest and lightest full frame compact system camera, and it was joined by the 36-megapixel A7R and high-sensitivity A7s. All three pose a serious challenge to the existing order of things, undermining the supremacy of full frame DSLRs in the professional photography and video market.
Most image stabilisation systems are built into the camera lens but a few makers, including Sony, add a stabilisation mechanism to the sensor itself.
The 5-axis stabilisation in the A7 II compensates for 'angular shake' (pitch and yaw), 'shift shake' and 'rotational shake' (roll). Sony says it allows shutter speeds up to 4.5 stops faster, and it's designed not just for stills photography but video too.
The A7's mirrorless design means that you're looking at the live sensor image both on the back of the camera and in the viewfinder, so you see the effects of the stabilisation as you compose your shots.
Some lenses designed specifically for Sony's full-frame E-mount cameras have optical image stabilisers built in already, but the new system could prove useful with unstabilised single focal length 'prime' lenses and older Sony a-mount lenses – these can be used with the A7 via an adaptor.
Business as usual
In other respects, the A7's specification are unchanged. The A7 II appears to use the same 24-megapixel full frame sensor as the original A7, and the maximum ISO (25,600), continuous shooting rate (5fps) and hybrid AF system (117 phase-detection points, 25 contrast-detection).
Sony does say, however, that new algorithms make the A7 II's AF system 30% more responsive and 1.5x better at following moving subjects. The startup time is said to be 40% faster too.
The new Sony A7 II should hit the dealers' shelves in January 2015, with prices to follow. In the meantime, take a look at our full Sony A7 review and keep checking the Techradar Camera Channel home page for all the latest camera reviews and news.