As shown in the figure, three identical polaroids \( P_{1} \), \( P_{2} \) and \( P_{3} \) are placed one after another. The pass axis of \( P_{2} \) and \( P_{3} \) are inclined at angle of \( 60^\circ \) and \( 90^\circ \) with respect to axis of \( P_{1} \). The source \( S \) has an intensity of \( 256 \, \mathrm{W/m^{2}} \). The intensity of light at point \( O \) is ________ \( \mathrm{W/m^{2}} \).
