Canon Patent Uses Refractive Index 2.2-2.3 Glass to Shrink Fast Primes

Canon patent JP 2026-167867,A describes a glass material with a refractive index of 2.2-2.3, above the range typically used in camera lenses, as a route to smaller, lighter fast prime designs. Per Canon Rumors, the patent focuses on the glass material itself rather than specific optical formulas.