Nikon D7500 has a
21.0MP APS-C (23.5 x 15.7 mm ) sized CMOS sensor and features Expeed 5 processor. On the other hand, Olympus E-520 has a
10.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor .
Nikon D7500's sensor provides 11MP more than Olympus E-520'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.
Another difference between these two cameras is that Nikon D7500's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the D7500 and E-520 sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D7500 and Olympus E-520 Cameras
As seen above, Nikon D7500 has a 1.6x Larger sensor area than Olympus E-520. 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 Nikon D7500 and Olympus E-520 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, D7500 has scored 86, 31 points higher than E-520.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D7500
86
24.3 bits
14.0 Evs
1483 ISO
Olympus E-520
55
21.4 bits
10.4 Evs
548 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
Nikon D7500
or the
Olympus E-520 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C 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.
