Quote by Drakkith
Yes, the intensity will be reduced.
The intensity of the light can be found by the following equation.
I=I_{0}cos^{2}θ_{i}
Where I_{0} is the initial intensity of the light before passing through the polarizer and θ_{i} is the angle between the light's initial polarization direction and the axis of the polarizer.

thank you very much, although I'm not up to that standard yet so I haven't come across it (I'm in high school here), the formula there makes sense, because cos 0 = 1, so the intensity would be exactly the same if the gap is in the exact plane as the wave's vibration, and cos 90 = 0 if the gap is right angle to the plane in which the wave vibrates in