Some of the newly released Pentax lenses have a new "exclusive HD coating technology" that offers improved light transmittance and a much lower refractive index. In their press release Pentax promises 50% reduction of reflections in the visible spectrum:
PENTAX develops multi-layer lens coating process for new HD PENTAX lenses
DENVER, CO (September 10, 2012) — PENTAX RICOH IMAGING AMERICAS CORPORATION(PENTAX), introduces today its newly developed HD Coating technology – a multi-layer lens coating process – for all new HD (High Definition) PENTAX lenses for PENTAX K-Mount cameras.
Compared with conventional multi-layer coatings, the new multi-layer HD Coating,* exclusively developed by PENTAX, offers much improved light transmittance and a much lower refractive index. Because this advanced coating minimizes reflections, the lens delivers sharp, clear images free of flare and ghosting, even under demanding lighting conditions such as backlight. This coating assures optical performance almost equal to Aero Bright Coating, another PENTAX-exclusive lens coating process made possible by advanced nanotechnology and applied to higher-class lenses.
“Our 37 year heritage of offering interchangeable photographic lenses demonstrates that PENTAX continues to be fully committed to producing the finest optics for our faithful PENTAX customers,” explains John Carlson, Sr. Manager of Sales and Marketing, PENTAX. “PENTAX is always looking for ways to improve upon our lens offerings by continuously improving the important behind-the-scenes coating technologies that help create crystal clear and colorful images that our customers can be proud of.”
Also introduced today is the new K-Mount HD PENTAX DA 560mm F5.6 ED AW interchangeable super-telephoto lens and the new HD PENTAX D FA 645 Macro 90mm F2.8 ED AW SR interchangeable lens for the medium format 645D – the first lenses to feature this exclusive PENTAX HD Coating. All future interchangeable lenses for PENTAX digital cameras that feature this new coating will bear the “HD PENTAX” name.
50 percent reduction of reflections in visible spectrum
The coating reduces reflections by more than 50 percent over the entire visible spectrum, compared to conventional multi-layer coating.
High rigidity coating layer
Since the HD Coating has a stronger bond among its coating materials and a higher packing density, this coating layer ensures exceptional high rigidity for extra durability.
Accurate reflection of design concept to actual coating layer
In conventional multi-layer processes, the coating layer is produced by the vacuum evaporation method, in which coating materials are dissolved and deposited in a vacuum. This method, however, sometimes causes coating unevenness great enough to affect image quality.
The HD Coating* effectively solves this problem by employing a PENTAX-exclusive manufacturing process, while optimizing the density of its coating layer and controlling the thickness with the accuracy of one nanometer (one millionth of a millimeter). As the result, the original design parameters for the lens coating are accurately applied to the coating layer to optimize anti-reflection performance of a lens.
* HD stands for High Definition, and signifies the lens’s capacity to reproduce images that excel in transparency, definition, resolution and rendition.