Schneider Circular Polarizer Multi-Coated Filter - 72mm

The Schneider Circular Polarizer Multi-Coated Filter - 72mm is a 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 image effect as linear polarization, but allows for proper exposure metering and/or autofocus distance settings. B+W Polarizers increase color saturation and reduce reflections. The neutral gray color and plane parallel polarizer material guarantee optimal image results. High-quality optical glass ensures excellent image 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.

This filter features a Multi-Resistant Coating (MRC), consisting of multiple layers that are harder than glass, protecting the filter from scratches (e.g., during cleaning). The coatings are also water and dirt repellent, facilitating easier filter maintenance.

This filter uses Schneider's standard B+W rotating F-Pro filter mount, which has a front accessory thread and is made of brass. Compared to the earlier standard mount introduced in 2001, the F-Pro mount is noticeably thinner and can now be used with wide angle lenses, including most 24mm focal lengths on a full frame body, without vignetting. Another advantage of the F-Pro mount is its modified retaining ring, which is no longer threaded in from the front, but holds the filter glass in place from the back. When removing a filter or lens hood that has been overtightened, the retaining ring is not at risk of loosening.

NOTE: Linear and circular polarizers both consist of a linear polarizer foil but differ in their construction. Modern SLR cameras feature a beam-splitting prism that sends part of the incoming light to the meter and part to the viewfinder. The effect is that the light entering the meter is partially polarized by the beam-splitter.

• A linear polarized filter placed on the lens of such a system will act as a second polarizer and block light to the meter by a degree dependent on the angle between the prism and the polarizer on the lens. The result is incorrect exposure/aperture values from the meter.
• The circular polarizer circumvents this problem through the addition of a 1/4-wave retarder, or delay, foil. This ensures that the linearly polarized light is changed into a rotation that appears unpolarized to the meter, resulting in proper exposure/aperture readings.