Below you can see the front view size comparison of Samsung NX300 and Pentax K-70. Samsung NX300 is clearly the smaller of the two cameras. Its body is 4mm narrower, 29mm shorter and 33mm thinner than Pentax K-70.
Samsung NX300 vs Pentax K-70 - Front View
Samsung NX300 vs Pentax K-70 - 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