Both Olympus XZ-1 and Canon S95 have 10.0 MP resolution sensors but Olympus XZ-1's sensor is 1/1.63-inch (8.07 x 5.56 mm ) and Canon S95's sensor is 1/1.7-inch (7.44 x 5.58 mm ).
Since Olympus XZ-1'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 S95.
Below you can see the XZ-1 and S95 sensor size comparison.
Sensor Size and Resolution Comparison image of Olympus XZ-1 and Canon S95 Cameras
Olympus XZ-1 and Canon S95 have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Olympus XZ-1 and Canon S95 sensors have been tested by DxO and the results show that S95 has a better overall score of 47, 13 points higher compared to XZ-1's score of 34.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Olympus XZ-1
34
18.8 bits
10.4 Evs
117 ISO
Canon S95
47
20.4 bits
11.3 Evs
153 ISO
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
Olympus XZ-1
or the
Canon S95 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/1.63-inch versus 1/1.7-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.