A/R & Light Transmision

[OPTIDONN]

Is there a way to figure out exactly how much a/r improves light transmision?

[Jan Post]

When I am discussing AR with cleints I explain that a non ar lens reflects aprox 8 to 11 percent of the light, with the AR applied(depending on manufacturer) reflection is reduced to aprox 1% therefore it reduces it but if your looking for specifics or ways to measure it I would consult with a company such as Essilor for any mesuring devices available

[Darryl Meister]

if your looking for specifics or ways to measure it I would consult with a company such as Essilor for any mesuring devices available

The transmittance of an AR-coated lens could probably be calculated mathematically with a computer (numerous calculations would be required to determine the performance of a multi-layer AR stack), though in practice the values you see quoted are most likely from spectrophotometer measurements of production samples. Generally, you can find out the performance typical of a particular brand of AR coating by contacting the supplier or manufacturer.

If you know the final transmittance of the lens, or even the final reflectance, you can assume that the AR coating has improved the performance of the lens by an amount roughly equal to this value minus the initial transmittance or reflectance of the lens material. Uncoated hard resin, for instance, reflects 7.7% of incident light, polycarbonate reflects 9.8%, 1.6 high-index plastic reflects 10.1%, and 1.66 high-index plastic reflects 11.7%. If a particular AR-coated polycarbonate lens transmits 99.0% of incident light, the AR coating has increased its performance roughly 8.8%.

Note that some AR suppliers may provide the average reflectance or transmittance of the lens, while others may provide the luminous reflectance or transmittance. Luminous measures are weighted by the sensitivity of the eye to various color.

Best regards,
Darryl