Below you can see the front view size comparison of Panasonic S1R and Sony A7S. Sony A7S is clearly the smaller of the two cameras. Its body is 22mm narrower, 16mm shorter and 49mm thinner than Panasonic S1R.
Panasonic S1R vs Sony A7S - Front View
Panasonic S1R vs Sony A7S - Top View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
Select Two Cameras for Size Comparison