What is Anti-Reflective coating?
Anti-Reflective coating (or AR Coating) is an optical coating that is applied to the crystal of certain watches in order to prevent it from reflecting light. There are multiple compounds readily available for application of watch crystals which differ in terms of AR performance, durability and legibility. For example, some AR coatings can give a slight blue tint to the crystal.
The objective of AR coating is to improve readability and performance of the crystal while keeping the clarity of the glass to its best.
In the watch industry, there are two ways to coat a crystal. Both methods have their advantages and drawbacks.
The first method is to coat both sides of the crystal. This will increase the AR efficiency but, comes at the cost of durability as AR coating can easily get scratched.
The second method intends to avoid this issue by coating only the bottom part of the crystal which is protected from scratches from the crystal itself. This however means that the AR efficiency is reduced (as only one side of the crystal is covered).
History of AR coating
AR coating was initially discovered by Lord Rayleigh in 1886 when he discovered that a slightly tarnished glass would let more light through than a brand new one which reflected more light.
However, the technique for creating and applying AR coatings was only perfected in 1935 by a Soviet scientist Olexander Smakula.
Understandably, by the end of WW2 pilot watches had AR coatings applied. When flying above the clouds, pilots were to brighter light which would easily bounce of glass. To prevent a situation in which the watch would become illegible, AR coating became industry standard on pilot watches.
Are Aeromat watches coated?
At Aeromat, we’ve looked in detail at the history of pilot watches and wanted to re-create the same product build quality as in the past. For this, we have chosen to apply AR coating to all of our collections. We believe that a pilot watch cannot be called such without this key feature. Our AR coating will guarantee legibility in all conditions and for everyone.
We’ve decided to coat only the inside of the crystal for increased durability. Indeed, an exterior AR coating can deteriorate rather quickly. In addition, when AR coating is scratched, it becomes highly visible due to the difference in reflection between the coated and scratched parts of the crystal.