Dura Coat is a unique AR coating which is ideally suited for anti-reflective applications that require both durability and high optical performance. Dura Coat resists fingerprints and smudges and can hold up to harsh treatment. It also makes an excellent cover glass to any optically bonded display. Additionally, Dura Coat is a great cover glass for Luminary Optics custom PCAP designs. DuraCoat AR is a uniquely formulated window specifically developed for the most rugged outdoor applications. The DuraCoat AR front coating is the most durable anti-reflecting (AR) coating available. The AR coating itself is less than .4% of specular reflectance. More importantly, DuraCoat AR resists all smudges and fingerprints. Due to its low surface tension, smudges literally wipe away without special cleaners using only a soft cloth. The coating is also durable - the AR coating has an 8H pencil hardness which can tolerate abrasions, with up to 450,000 rubs without lifting or damage to the coating. DuraCoat AR can also survive a 90 day salt-fog test as well as a variety of other accelerated acid spray tests.
AR coatings, with their index match properties to air, reduce surface reflections to as low as .35%. With this dramatic change, the use of AR coatings should have broad use and appeal. There is, however, a downside to AR coating. Since the AR coating matches the surface of glass to air, any amount of oil or grease caused by fingerprints and other sources that cling to the glass can cause reflection issues. The oil of a fingerprint is not indexed matched. This means that the fingerprint alone will be reflecting 4.5% of the ambient light while the rest of the display is reflecting little. This means that the fingerprint will all but glow against its surrounding background. This means the display will increasingly show the fingerprints, looking smeared and unappealing. As fingerprints show up on AR glass, the tendency is clean the glass. Unless care is given, most AR coatings can literally be polished off the glass with repeated cleaning. Additionally, AR coatings are a metal. In a salt-fog application, such as marine navigation, the salt atmosphere becomes corrosive to the AR coating and it can be damaged.