Canon S120 has a
12.0MP 1/1.7-inch (7.44 x 5.58 mm ) sized BSI-CMOS sensor and features Digic 6 processor. On the other hand, Olympus E-M1 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features TruePIC VII processor.
Below you can see the S120 and E-M1 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon S120 and Olympus E-M1 Cameras
As seen above, Olympus E-M1 has a 5.4x Larger sensor area than Canon S120. 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.
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. Canon S120 and Olympus E-M1 sensors have been tested by DxO and the results show that E-M1 has a better overall score of 73, 17 points higher compared to S120's score of 56.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon S120
56
21.3 bits
11.9 Evs
246 ISO
Olympus E-M1
73
23.0 bits
12.7 Evs
757 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
Canon S120
or the
Olympus E-M1 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(1/1.7-inch versus Four Thirds),
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.
