Sony defined a category when it rolled out the enthusiast-focused Cyber-shot DSC-RX100. This shirt pocketable compact's fourth iteration brings a new 20MP 1"-type stacked CMOS sensor to the table, maintaining an F1.8-2.8, 24-70mm equivalent zoom lens from the preceding model. The RX100 IV looks a whole lot like the cameras that came before it, but it presents a number of updates that could add up to a very different experience for the user. Take a look at our comprehensive analysis.