Canon R3 has a
24.0MP Full frame (36 x 24 mm ) sized Stacked CMOS sensor and features Digic X processor. On the other hand, Panasonic GH3 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine VII FHD processor.
Canon R3's sensor provides 8MP more than Panasonic GH3'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 R3 and GH3 sensor size comparison.
Sensor Size and Resolution Comparison image of Canon R3 and Panasonic GH3 Cameras
As seen above, Canon R3 has a 3.8x Larger sensor area than Panasonic GH3. 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 Canon R3 and Panasonic GH3 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, R3 has scored 96, 25 points higher than GH3.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon R3
96
25.0 bits
14.7 Evs
4086 ISO
Panasonic GH3
71
22.7 bits
12.4 Evs
812 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 R3
or the
Panasonic GH3 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(Full frame 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.