Both Canon SX280 HS and Sony A7S III have 12.0 MP resolution sensors but Canon SX280 HS's sensor is 1/2.3-inch (6.17 x 4.55 mm ) and Sony A7S III's sensor is Full frame (35.6 x 23.8 mm ).
Since Sony A7S 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 Canon SX280 HS.
Below you can see the SX280 HS and A7S III sensor size comparison.
Sensor Size and Resolution Comparison image of Canon SX280 HS and Sony A7S III Cameras
As seen above, Sony A7S III has a 30.2x Larger sensor area than Canon SX280 HS. 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
Canon SX280 HS
or the
Sony A7S III ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3-inch 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.
