Panasonic has over a decade of experience making mirrorless cameras, so it's a bit surprising that the S1 & S1R are the company's first to use full-frame sensors. The experience shows. The S1 is well-rounded, with advanced video capabilities and a 24MP sensor. The S1R is built for those who need maximum resolution and is based around a 47MP sensor with a 187MP "High Res" sensor-shift mode. Both cameras are fully weather-sealed, with 5.76M-dot, 120Hz OLED electronic viewfinders, 5-axis in-body image stabilization systems, dual-hinged touchscreen LCDs, quick contrast-detect AF systems, and support for both XQD and SD cards. They both use L-mount glass, a Leica-owned system that will include lenses from Panasonic, Sigma, and Leica themselves.