Canon 5D MII has a
21.0MP Full frame (36 x 24 mm ) sized CMOS sensor and features Digic 4 processor. On the other hand, Canon 70D has a
20.0MP APS-C (22.5 x 15 mm ) sized CMOS sensor and features Digic 5+ processor.
Below you can see the 5D MII and 70D sensor size comparison.
Sensor Size and Resolution Comparison image of Canon 5D MII and Canon 70D Cameras
As seen above, Canon 5D MII has a 2.6x Larger sensor area than Canon 70D. 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 5D MII and Canon 70D 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, 5D MII has scored 79, 11 points higher than 70D.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Canon 5D MII
79
23.7 bits
11.9 Evs
1815 ISO
Canon 70D
68
22.5 bits
11.6 Evs
926 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 5D MII
or the
Canon 70D ,
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.