Energetic 8‐nsec laser pulses were focused on Al, Au, and Cu foils ranging in thickness from 0.1 to 9 &mgr;m. The transmitted laser light was recorded and the plasma expansion from the front and back surfaces of these foils was measured using Thomson parabola and Faraday cup diagnostics. Comparison of the front‐ and back‐surface Thomson parabola traces clearly shows the change from ablatively driven behavior to nearly symmetric exploding‐pusher behavior for all of the materials.