World's first Full-frame back-illuminated Exmor R CMOS sensor with 42.4 megapixels
The newly developed 35mm Exmor R CMOS sensor is the world's first full-frame sensor with back-illuminated structure. The structure combines gapless on-chip lens design and AR (anti-reflective) coating on the surface of the sensor's glass seal - with no low-pass filter - to dramatically improve light collection efficiency, even though the pixels are smaller than the ones in the a7R. Moreover, the wiring layer now uses copper (instead of aluminum) wiring for faster transmission speed. The results are truly remarkable with incredibly detailed 42.4 megapixel stills and 4k video with high sensitivity - up to ISO 102,400, low-noise performance and wide dynamic range that are superior to previous models.

5-axis in-body image stabilization optimized for 42.4MP full-frame
The 5-axis SteadyShot INSIDE image stabilization system is fine-tuned for high-resolution image sensors. It accurately compensates for blur caused by camera shake from five different directions vertical, horizontal, pitch, yaw and roll as opposed to only two in previous systems. The 5-axis image stabilizing system excels during video recording and even compensates for blur caused by the photographer walking or running. It's a true marvel of engineering. You can even monitor the stabilizing effects of camera shake compensation in the viewfinder or LCD screen while shooting still images by pressing the shutter button halfway or magnifying the image, and while shooting movies by entering movie mode.

4K movie recording 5 with full pixel readout and no pixel binning
The a7R II is the world's first camera to offer 4K movie recording to internal media