I'm no expert, but I see your EV is at -0.33. Perhaps if it was increased to -0.66. I have a zs15 and find that Pannys tend to blow-out whites when at EV 0. I almost have to change the EV from -0.33 to -0.66 depending on how bright it is. Try a few at -0.66 and see if it improves. Note that you may have to do a little fiddling in some post processing program to lighten the image bring forward dark areas, but the detail would remain.