Circular polarizing filters are made 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.
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
plano-parallel optical glass. The resulting sandwich is then precision-polished
again to achieve highly accurate plano-parallel surfaces.
Subsequently they
are edge-sealed to protect the foil against humidity. 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.
The nano coating is an outer layer of protection that comes standard
with all XS-Pro Digital MRC filters.
The nanotechnology based characteristic (lotus effect) produces a
better beading effect with water making the cleaning of this filter even
simpler and faster than ever before. MRC nano has an improved outer
(8th) layer over regular MRC.
MRC by B+W is not only an extraordinarily effective
multiple layer coating, it is also harder than glass, so that it protects filters
from scratches (for instance when cleaning the filters), and it is also water
and dirt repellent, thus facilitating filter maintenance.
This filter uses our rotating XS-Pro Digital mount which is especially
suited for
DSLRs with wide angle and zoom lenses. It has a front thread for
additional accessories such as lens caps or hoods. All XS-Pro Digital
mounts are made
of brass and are matte black to prevent reflections.