Both Sony QX30 and Canon 70D have 20.0 MP resolution sensors but Sony QX30's sensor is 1/2.3' (6.17 x 4.55 mm ) and Canon 70D's sensor is APS-C (22.5 x 15 mm ).
Since Canon 70D'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 QX30.
Below you can see the QX30 and 70D sensor size comparison.
Sensor Size and Resolution Comparison image of Sony QX30 and Canon 70D Cameras
As seen above, Canon 70D has a 12.0x Larger sensor area than Sony QX30. 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 QX30
or the
Canon 70D ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/2.3' versus APS-C),
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.
