Product Description
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High Quality German Filters
From the Manufacturer
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Protect Your Lens while Reducing UV Exposure (486M)
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This B+W Interference Filter has a completely colorless glass
carrier coated with a number of extremely thin, partially
reflecting layers with precisely computed thicknesses, similar to
MRC coating. It does not block by means of absorption, but by
interference of the unwanted UV and IR radiation that is
repeatedly reflected between these layers, affecting the
wavelengths on both sides of the visible spectrum with a steep
cut-off. It is used mainly on digital and video cameras with CCD
sensors without an integrated IR protection filter, because the
IR sensitivity of the CCD sensor would otherwise cause color
changes and unsharpness. That unsharpness results from the
chromatic aberration of the lenses that are only corrected for
visible light. In the visible range, the transmission curve is
very high and straight. This filter is completely clear and it
requires no increase in exposure. It has a filter factor of 1.
Important Note Regarding Wide-Angle Lenses
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Please note however that, in contrast to mass-colored (integrally
colored) filter glass, the UV/IR Cut MRC (486M) filter is based
on thin-film technology. More than 30 interference coatings are
vapor-deposited on one side, while the site side is
MRC-coated. In wide-angle lenses, the laws of physics lead to
shallower incidence angles for peripheral rays. For geometric
reasons these rays have to travel further through the
interference coatings than rays traveling vertically through the
coatings in the center of the lens. With increasing angle of
incidence, this leads to a change in light color towards blue.
This effect can clearly be seen by looking at an UV-IR barrier
filter from an angle. The color of the reflected light changes,
with a similar effect on the light traveling through the filter.
The filter is therefore not suitable for lens systems with an
angle of view greater than 60°. The pictures gain brilliance and
disturbing blue casts are avoided. Because the glass is
colorless, color rendition is not altered, aside from the
elimination of the unwanted blue cast, and no increase in
exposure is required. That makes a UV filter very suitable as
protection of the front element of the taking lens against dust,
flying sand, sea water spray, and the like, and it can be kept on
the lens at all times. It is recommended for analog color and
black-and-white, as well as digital photography.
MRC - A Special Scratch-Resistant, Water and Dirt Repelling
Coating
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The left half of this filter has a
traditional coating. The right half
has MRC coating.
The lens elements of high-quality lenses and the plano surfaces
of filters require a perfect shape and smoothness to achieve the
best optical quality. Dirt, greasy fingerprints, water marks and
scratches reduce the image contrast and the sharpness, which can
result in blooming at light sources and have an effect similar to
a soft-focus lens. A clean front lens element and clean filter
surfaces are therefore an absolute pre-requisite for demanding
photographers.
MRC coating causes the water
to bead up and slide right off.
The MRC coating is first and foremost a broadband
anti-reflection coating. This means that its reflection-reducing
effect, which is thus also a transmission-increasing effect, i.e.
one which suppresses scattered light and ghost images and
transmits more light, has a broadband action over the full
spectrum. In contrast, the (almost always blue) single-layer
coating only has a high effect in the medium wavelength range
around yellow and yellow-green where the eye is most sensitive to
light, while its effect is greatly reduced toward the blue-violet
and purple-red end regions of the visible spectrum. With the MRC
coating, this blue, violet and red to deep-red light cannot
produce any contrast reducing scattered light, spotty reflections
or ghost images. A broadband effect can only be achieved with a
multilayer coating which requires a much higher effort and
precision because unevenness and irregularities of the individual
layers build up on one another and amplify one another. Schneider
therefore uses a plasma-assisted evaporation coating process in
which inert ions accelerated in an electrical field compact
the material deposited on the lens surface in the vacuum chamber.
For photographers, the main advantage of MRC coating, is it's
ability to combat flare and ghosting. An added benefit is that
their filters remain free of dirt longer, so that they do not
have to be cleaned so often. When cleaning the filter does become
necessary, it is a lot easier to wipe off the dirt with a blower
brush, because of MRC's ability to repel dirt and moisture. This
also reduces the risk of micro-scratches which can occur during
cleaning.
Side view of F-Pro .
Click for larger view.
F-Pro Brass Filter
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This filter uses our standard B+W F-Pro filter , which has a
front accessory thread and is made of brass. Compared to the
earlier standard , the F-Pro , 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 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.
- About this item.
- Brass Ring for higher Quality Image Highest possible polishiing technique World's best optical glass New thinner Pro . No vignetting.