The front line of image control

The front line of image control The new ARRI Full Spectrum Neutral Density filter serves as the front line of image control. A logical addition to ARRIs high-quality product line, this external FSND filter not only offers protection but has a palpable effect on image quality.

Due to the increasingly high expectations for modern deliverables, current industry image quality demands such as Ultra HD, High Dynamic Range, and Wide Color Gamut, and a growth in customer and end-user demand for top-quality external filters, ARRI was inspired to create its own FSND external filter. ARRI is already very familiar with premium filters; the ALEXA Mini and the AMIRA cameras come equipped with an internal FSND filter that is highly respected in the industry for its pure color neutrality. Based on this expertise, ARRI is now expanding on its offerings with additional front filters complete with premium coatings and direct part marking.

GLASS QUALITY AND UNIQUE FEATURES

The optical-quality, Schott B270i glass used in the ARRI FSND filter is manufactured to a very high standard. The glass is polished completely flat on both sides of the filter, with completely parallel surfaces. Plane parallelism is especially important when using a wide-open telephoto lens, as areas of the focal plane can become soft. FSND filters reduce the amount of light entering the lens, allowing the filmmaker to shoot at wider T-stops under bright conditions without overexposure. FSND filters make it possible to blur moving elements such as water or traffic in bright conditions. The ARRI FSND filter comes in 6.6 x 6.6 and 4 x 5.65 sizes.

Different from most competing external filters which have square, bumpy edges, the edges of the ARRI FSND filters are perfectly c-shaped. This curved edge reduces glass chipping and makes for easier and safer mounting. ARRI's FSND filter edges have also been colored black to prevent the scattering of light. Close to the filter's edge, the glass surface also features an engraved unique direct part marking (DPM), which will improve inventory security for rental houses and for individual owners. This GS1 bar code, which is readable by most camera-based bar code readers around the world, makes rental check-ins and check-outs easier, provides proof of ownership, and eliminates the need for stickers that can fall off or leave residue on the filter.

EXPERT COATINGS

Not only have the filter materials and shape been expertly selected, but ARRI has devoted a great deal of time and energy to the various coatings of the ARRI FSND filters. Multiple layers of ND coating, anti- reflective (AR) coating, hydrophobic coating, oleophobic coating, as well as a final hard coating have been applied to both sides of the filter (a feature only offered by ARRI). Standard air-facing filters have a reflectivity rating of 4%-6% at each air-glass surface, but ARRI has been able to achieve 0.2% reflectivity. Since crews often stack filters together and reflectivity is cumulative, reducing this aspect down by a factor of 20 is a sensation. Reducing reflectivity maximizes contrast, allowing the full dynamic range of the sensor to be captured, facilitating HDR workflows. The additional coatings, hydrophobic and oleophobic, keep water and grease, respectively, from adhering to the surface of the glass, thereby cutting down on cleaning time dramatically. The hard coating, used to prevent scratches on the filter, is extremely durable and resistant to wear and tear. In tests, competitor filters were far less able to withstand repeated rubbing or cleaning in the same area without leaving a mark. This coating makes the filters more robust and extends their life, prolonging the return on investment.

LINK:	http://www.arri.de/news/news/the-front-line-of-image-control/...
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