Lets say that I were to perform the double slit experiment so that at any one time only a single photon passes through the double slit at a time. Now lets say that I were now to place a polaroid film over each of the slits so that each piece of the film was orthogonal to the other. Now in front of the newly polarized double slit I will place a second piece of polaroid film which is oriented in parallel with the left slit. At this point I become slightly confused so I will tell you what I think is happening and I would really appreciate if someone can tell me if I am right or wrong. 1) As a photon passes through the polarized slits it interferes normally with itself as if the films were not in place. 2) Then, as the photon strikes the second piece of polaroid film the wave function that was a result of the double slit interference pattern collapses because we measure the polarization of the photon and we are left with the wave function of a photon passing through a single slit. Is my reasoning correct? Thanks guys!!!