Both Nikon D7500 and Canon 5D MII have 21.0 MP resolution sensors but Nikon D7500's sensor is APS-C (23.5 x 15.7 mm ) and Canon 5D MII's sensor is Full frame (36 x 24 mm ).
Since Canon 5D MII'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 Nikon D7500.
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 5D MII sensor size comparison.
Sensor Size and Resolution Comparison image of Nikon D7500 and Canon 5D MII Cameras
As seen above, Canon 5D MII has a 2.3x Larger sensor area than Nikon D7500. 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 Canon 5D MII 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, 7 points higher than 5D MII.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Nikon D7500
86
24.3 bits
14.0 Evs
1483 ISO
Canon 5D MII
79
23.7 bits
11.9 Evs
1815 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
Canon 5D MII ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus Full frame),
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.
