B+W 77mm Kaesemann Linear Polarizer

by B&W

Product Details

• Product Dimensions: 3.1 x 3.1 x 0.4 inches ; 2.1 ounces
• Shipping Weight: 1 pounds (View shipping rates and policies)
• Shipping: Currently, item can be shipped only within the U.S.
• ASIN: B0012LO0EI
• Item model number: 65-075236
• Date first available at Amazon.com: June 17, 2003

Product Description

Size: 77mm

From the Manufacturer

Käsemann Linear Polarizers - The Highest Quality Polarizer Available

The images on the left was taken without any filter.
Notice the increased color saturation and reduced
reflections in the image on the right, taken with a
B+W Polarizer. Click for larger view.

Käsemann polarizing foils are neutral in color, have a higher efficiency than conventional polarizing foils, and are cemented between high-grade plano-parallel optical glass, using a special cementing technique that resists delamination in humid climates. The resulting sandwich is then precision-polished again to achieve highly accurate plano-parallel surfaces. Discriminating photographers regard the B+W Käsemann Polarizer as the very best polarizer on the market. They are well suited for applications that require the highest possible imaging quality, especially with high-speed telephoto lenses and apochromatic lenses.

B+W Polarizers increase color saturation and reduce reflections. The filter factor varies according to how the filter is positioned in relation to the sun. Exposure compensation is about two f-stops.

Not for Use with Beam-Splitting Prisms

Modern DSLR cameras have 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. If you have such a camera, you should instead use a circular polarizer. A linear polarizer 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.

Uncoated for Greater Effect

The glass of this filter is uncoated. This is common with special effects filters, where coating is either an impossibility or would work against the effect the filter is trying to attain.

Side view of F-Pro Rotating
Mount. Click for larger view.

F-Pro Brass Filter Mount

This filter uses a rotating B+W F-Pro filter mount for added creative options. The mount has a front accessory thread and is made of brass. Compared to the earlier standard mount, the F-Pro mount, introduced in 2001, has become thinner. Now it can 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 screwed on too tight to the filter, the retaining ring is not at risk of loosening.

Product Description

The "high-end" polarizing foils of the Käsemann-type filters are neutral in color, they have a higher efficiency than conventional polarizing foils and they are cemented between high-grade plane-parallel optical glass. The resulting sandwich is then precision-polished again to achieve highly accurate plane-parallel surfaces. Subsequently they are edge-sealed to protect the foil against humidity. Brass mounts made on CNC-controlled machines ensure precise seating on the lens. Discriminating photographers regard the B+W Käsemann-Type Polarizing Filter to be the very best of all polarizing filters. They are well suited for applications that require the highest possible imaging quality, especially with high-speed telephoto lenses and apochromatic lenses.