Both Sony RX10 IV and Canon 1D X III have 20.0 MP resolution sensors but Sony RX10 IV's sensor is 1″ (13.2 x 8.8 mm ) and Canon 1D X III's sensor is Full frame (36 x 24 mm ).
Since Canon 1D X III's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Sony RX10 IV.
Below you can see the RX10 IV and 1D X MIII sensor size comparison.
Sensor Size and Resolution Comparison image of Sony RX10 IV and Canon 1D X III Cameras
As seen above, Canon 1D X III has a 7.4x Larger sensor area than Sony RX10 IV. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony RX10 IV
or the
Canon 1D X III ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1″ versus Full frame),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
