Dpreview: The EOS R1 is built around an all-new 24.2MP Stacked CMOS sensor. It's a faster sensor than we've seen in previous Canon cameras and has a full sensor readout rate of 2.8ms (1/360) when shooting stills. That compares to just under 5ms on the EOS R3, making the R1's full sensor readout nearly twice as fast as the R3's.