Thin plastic foils (2~10 μm thickness) were irradiated with the iodine laser ASTEEIX III (λ=1.3 μm) Pulse energy was 100 J, pulse duration 300 ps; the intensity on target was varied in the range 1014?5x 10炀 W.cm-2- An active-passive mode-locked,fJash -lamp-pumpad dye laser was synchronized with the iodine laser pulse. A siaglo dye ]asei pulse (?10 ps duration) was used to study the gasdynamic motion of the foil matexial during and aifter irradiation by shadowgraphy. Besides the expected acceleration of tZie foil under one-side irradiation we also find strong distuxbaneea of the foil at distances far from the irradiated area, especially at high irxadiances. The results will be discussed and compared with previous, calorimetric measurements of thin foil acceleration.