Both Sony A7S and Canon SX280 HS have 12.0 MP resolution sensors but Sony A7S's sensor is Full frame (35.8 x 23.9 mm ) and Canon SX280 HS's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Sony A7S'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 A7S and SX280 HS sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A7S and Canon SX280 HS Cameras
As seen above, Sony A7S has a 30.5x 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
Sony A7S
or the
Canon SX280 HS ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Full frame versus 1/2.3-inch),
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.
