Lee SW150 Polariser When sunlight hits a flat, non-metallic surface, such as water or glass, it is polarized. That is, it only swings in one plane. Depending on the position of the polarizing filter, this plane can be let out, removed or attenuated. The application leads to fewer reflections & unsightly reflections as well as to a more saturated representation of the sky. The SW150 system has a circular polarizing filter. If used alone, the polarizer can be placed in the filter holder & the holder is rotated until the desired effect is achieved. This polarizing filter is ideal for Autofocus cameras. When fully effective, it reduces the light by 1.5 f-stops. Looking for the right Lee Filter for you? Use Lee’s System Match tool to find what’s compatible with your equipment.