Sony has introduced the fourth generation of its popular Alpha 7R mirrorless camera. Along with all the improvements that could be expected from the new installment of the series, Sony has also introduced the world’s first full-frame back-illuminated (BI or BSI) sensor, with a 61-Megapixel resolution. 
It’s another interesting example of cross-pollination between smartphones and professional cameras: BSI sensors, capable of detecting more light, thus enhancing low-light performance, where originally way smaller sensor designed to bring better exposure range to smartphones. The improvements of the iPhone 4’s camera, for example, were based mostly on the introduction of such a sensor. 
Fast-forward nine years, count in the mirrorless revolution, also spearheaded by Sony, and here we are, with a new full-frame mirrorless with 61-Megapixel resolution that leapfrogs the resolution of most medium format cameras, and quite a long list of computational enhancements, with a blazingly fast auto-focus with eye- and subject-tracking capabilities and 567 points of phase detection, a 15-stops dynamic range and impressive video capabilities that will certainly please filmmaking professionals. 
Price: £3499 for the camera body.