Highly efficient standard circular polarizing filter for all cameras with beam splitters in the light paths of their TTL exposure meter and with autofocus lenses. Circular polarization has the same pictorial effect as linear polarization, but allows for proper exposure metering and/or autofocus distance settings. B+W Polarizers increase color saturation and reduce reflections. High-quality optical glass ensures excellent pictorial quality. The filter factor varies according to how the filter is positioned in relation to the sun. Filter factor is between 2.3 and 2.8.