There are two polarizing filters that are out of alignment by 30 degrees. If the light of intensity 1.00 W/m^2 and initially polarized half-way between the two filters passes through the two filters, what is the intensity of the transmitted light?

Question

I know the answer is 0.700 W/m^2, but I have no clue how to find that answer.
Thank you for any help!

Answer 1

The fraction that gets through the first fiter is (cos15)^2 = 0.9330

The fraction of that which gets through the second filter is (cos30)^2 = 0.7500

Now take the product.

Actually, sheet polarizing "Polaroid" films lose even more than that, due to absorption.

Answer 2

The intensity of the light isn't halved after it passes through each filter? That's what I don't understand.
Thank you for your help!