Oh, i think I'm wrong with this sentence:
Quote: but remains way behind the nano-coatings of Canon/Nikon
The statements from PENTAX are that it is close to the Pentax's Aero-bright Coating (but I don't know how this Aero-bright coating "scores" compared to the Nikon's Nano Coating). And if PENTAX shows us a comparison between standard SMC and HD coatings, they give us no comparison with Aero-bright coating.
For the rest of my statement:
Quote: I don't think that HD is nano-coating or may be compared to nano-coating !
It's just an improved version of the SMC coating,
I think my point of view is correct ...
See this :
Quote: DE:
You've got another coating, the "Aero Bright" coating, and it seems like both of those were used together in the 90mm. How do they differ? Are they serving different functions?
JC: The
Aero Bright coating is for internal surfaces of the lens. It reduces internal reflections, and changes the refraction of the light through the lens. But it's not as durable as the HD coating, whereas the
HD coating is appropriate for external lens surfaces. It's more durable, and it accomplishes the same goals. If you put them together, you end up with a great lens.
DE:
Got it. I'm not sure what technology you're using, but I know that the nano coatings tend to be soft coatings, so they're very easily damaged.
JC: Yes.
from:
Q&A with Pentax’s John Carlson: A deeper look inside the new MX-1, Pentax’s ILCs and lenses
Also this:
Quote: PENTAX - PENTAX Announces New 90mm Macro Lens
HD PENTAX D FA 645 MACRO 90mm F2.8 ED AW SR lens
This lens is treated with HD Coating*, a newly developed, high grade multi-layer lens coating , which offers higher light transmittance with reduced reflection, to deliver sharp, clear images free of flare and ghosting, even under demanding lighting conditions such as backlight. By coupling this coating with the PENTAX-exclusive, high grade Aero Bright Coating,** this lens optimizes light transmittance while minimizing refraction.
* HD stands for High Definition, and signifies the lens’s capacity to reproduce images that excel in transparency, definition, resolution and rendition.
** A PENTAX-original lens coating process developed through the use of advanced nanotechnology. Using a silica aerogel with a uniform porous structure as the base material, this coating produces clear, high-quality images by assuring an outstanding anti-reflection performance over a broad wavelength range.
For the Aero-bright coating, PENTAX speaks of Nanotechnology, NOT for the HD coating.
In your description, Kunzite, PENTAX does not speak of nanotechnology, but of the thickness and accuracy of the layer (and the process to achieve this). ;-)