Both Canon 70D and Canon 7D MII have 20.0 MP resolution sensors but Canon 70D's sensor is APS-C (22.5 x 15 mm ) and Canon 7D MII's sensor is APS-C (22.4 x 15 mm ).
Since Canon 70D'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 Canon 7D MII.
Below you can see the 70D and 7D MII sensor size comparison.
Canon 70D and Canon 7D MII have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the 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 70D and Canon 7D MII sensors have been tested by DxO and the results show that 7D MII has a better overall score of 70, 2 points higher compared to 70D's score of 68.
Model |
Overall |
Color Depth |
Dynamic Range |
Low-light ISO |
Canon 70D |
68 |
22.5 bits |
11.6 Evs |
926 ISO |
Canon 7D MII |
70 |
22.4 bits |
11.8 Evs |
1082 ISO |