B+W 010M 1066124 Fascicule

SEPTEMBER 2006  ·  FOR IMMEDIATE RELEASE

Jos. Schneider Optische Werke GmbH
Business Unit Photo
Ringstr. ¡32 · D-55543 Bad Kreuznach
Phone:  +49 67¡ 60¡-¡25
Fax: 

+49 67¡ 60¡-302

foto@schneiderkreuznach.com
www.schneiderkreuznach.com

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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 or scratches 
reduce the image contrast and the sharpness, result in blooming at lights and can generally have an 
effect similar to a soft-focus lens. Clean front lenses and glass filter surfaces are therefore an absolut 
pre-requisite for demanding photographers.
 

SCHNEIDER-KREUZNACH developed the MRC special coating more then ten years ago and has 

since used it on the exposed front and rear surface of all the B+W filters marked with “MRC” and on 
the unique B+W clear glass protective filter 007 Clear. The coating has a dual-action to keep surfaces 
clean and smooth: The MRC (“multi-resistant coating”) coating is an extremely highly resistant multi-
layer broadband coating with two key features in addition to the reduction of reflections and an 
increase in transmission over the total visible spectral range:
l

  first, a hydrophobic (water-repellent) and incredibly smooth surface which makes water roll off 

instead of wetting the lens element or filter and so also keeps most of the dirt off; and
l

  second, extreme hardness which provides mechanical protection against scratching in the rough 

and tumble conditions of everyday photography or when cleaning the lens elements or filters.

¡0 years of MRC = ¡0 whole years in advance of everyone else with a solution proven in practice
 

This year saw some competitors introduce their first lenses or filters with a water and dirt repel-

lent coating said to be based on the “lotus effect”. In actual fact, however, neither the MRC coating of 
SCHNEIDER-KREUZNACH nor the coatings of our competitors introduced a good ten years later 
offer a “lotus effect” (named after the water-repellent lotus flower). This effect is based on a submi-
croscopically finely structured surface which – like the greasy pelt or feathers of some animals – 
does not allow water droplets to penetrate into the intermediate spaces, but causes them to float on 
them as spheres and then roll off. However, a surface structure in the order of nanometers would be 
mechanically extremely sensitive, if it could be manufactured at all with the required precision. Its 
cavities could fill up with very fine particles and their peaks could break off or be worn off so that 
the water-repelling effect is cancelled out there. SCHNEIDER-KREUZNACH therefore does not use 
this incorrect “lotus” designation, but explains the effect of the MRC coating correctly as follows: 

A plasma-assisted evaporation coating method generates a top coat with low surface tension
 

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 suppress-
es 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 medi-
um 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 spec-
trum. With the MRC coating, this blue, violet and red to deep-red light cannot produce any contrast-

For continuation 
and photos see page 2