Sony's original RX100 — the camera that created the 1-inch compact category with f/1.8 Zeiss zoom.
The Sony Cyber-shot DSC-RX100 (original Mark I) was released in 2012 as a premium compact featuring a 20.2MP 1-inch Exmor CMOS sensor — the first consumer compact with a 1-inch sensor — and Carl Zeiss Vario-Sonnar T* 28-100mm f/1.8-4.9 zoom. 1080p/30fps video. At 240g.
20.2MP 1-inch Exmor CMOS. Zeiss 28-100mm f/1.8 (wide) to f/4.9 (tele) equivalent. 1080p/30fps — note: 60fps was added in Mark II. Optical SteadyShot. Manual ring on lens. NP-BX1 battery. At 240g. Fixed zoom — no interchangeable mount.
The original RX100 introduced the 1-inch sensor to compact cameras: the significantly larger sensor versus the 1/2.3-inch standard in compacts provided major improvements in dynamic range, low-light sensitivity, and depth-of-field control. The f/1.8 wide-end aperture with 1-inch sensor enables selective focus previously unavailable in compact cameras. The Mark I lacks the Multi Interface Shoe added in Mark II.
On the used market the Sony RX100 Mark I is very affordable as a 1-inch compact. Condition checks: NP-BX1 battery health, Zeiss zoom mechanism, sensor for hot pixels. Note: 1080/30fps only (no 60fps — that's Mark II). Fixed 28-100mm zoom — no interchangeable mount.