compound which makes the molecules conductive so they absorb light whose electric field is parallel to the molecular chains the resultant polarizing filter blocks waves with electric fields along the molecular axes and passes waves with perpendicular electric fields the output is a beam which is linearly polarized along the preferred axis metering and auto focus sensors in certain cameras including virtually all auto focus single lens reflect cameras may not work properly with a linear polarizer because the beam splitters used to split off the light for focusing and metering are polarization dependent a circular polarizer may include a linear polarizer on the front which selects one polarization of light while rejecting another followed by a quarter wave plate which converts the selected polarization to circularly polarized light inside the camera which works with most all types of cameras because mirrors and beam splitters split circularly polarized light the same way they split unpolarized light polarizing window 120 may be configured to have a substantially circular cross section sized to securably fit inside the interior of hood body 110 in an embodiment polarizing window 120 is positioned with the center of its face perpendicular to the axis running through hood body 110 facing end 117 the polarizing filter of polarizing window 120 may be oriented in any suitable orientation such as with the 0 axis of the polarizing filter directed to the top of hood body 110 e g twelve o 39 clock alternatively polarizing window 120 may be oriented to optimally interact with known or measured properties of the provided light source the polarizing filter selected.