How Much Reflection Can An Index-Matched AR Stack Reduce?
An index-matched AR stack can reduce lens reflection by a large amount, especially when compared with uncoated glass or plastic lenses. A plain glass surface can reflect about 4% of incoming light per surface, while a simple single-layer AR coating can bring that closer to 1% in some designs. More refined multilayer AR coatings can push average reflection below 0.5% per optical surface, and some narrowband coatings can reach below 0.25% at the target wavelength. In practical terms, that means the right AR stack can cut visible surface reflection by roughly 85% to 95%, depending on the lens material, coating design, wavelength range, and viewing angle.
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