gliding camera physics

k = 2; // some number that controls the snappiness of the camera
offset = 480; // where you want the camera to settle relative to the player

camera.targety = player.y + offset;
if(camera.targety > camera.y)
  camera.velocity.y = (camera.targety - camera.y) * k;
else
  camera.velocity.y = 0;
camera.y += camera.velocity.y * deltatime;