Below you can see the front view size comparison of Canon 1Ds MIII and Nikon Z7. Nikon Z7 is clearly the smaller of the two cameras. Its body is 16mm narrower, 59mm shorter and 12mm thinner than Canon 1Ds MIII.
Canon 1Ds MIII vs Nikon Z7 - Front View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
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