Sony A7S II has a
12.0MP Full frame (35.6 x 23.8 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Canon SL2 has a
24.0MP APS-C (22.3 x 14.9 mm ) sized CMOS sensor and features DIGIC 7 processor.
Canon SL2's sensor provides 12MP more than Sony A7S II's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Below you can see the A7S II and SL2 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A7S II and Canon SL2 Cameras
As seen above, Sony A7S II has a 2.5x Larger sensor area than Canon SL2. 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
Both Sony A7S II and Canon SL2 sensors have been tested by DxoMark. DxoMark 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. Of the two cameras that we are comparing, A7S II has scored 85, 6 points higher than SL2.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A7S II
85
23.6 bits
13.3 Evs
2993 ISO
Canon SL2
79
23.6 bits
13.4 Evs
1041 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
Sony A7S II
or the
Canon SL2 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Full frame 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.