  Polarizers are key components in optical science and technology. Thus,
understanding the action of a polarizer beyond oversimplifying approximations
is crucial. In this work, we study the interaction of a polarizing interface
with an obliquely incident wave experimentally. To this end, a set of Mueller
matrices is acquired employing a novel procedure robust against experimental
imperfections. We connect our observation to a geometric model, useful to
predict the effect of polarizers on complex light fields.
