so we all know this website on lens aging
some random qns.
what if the date code is not stamped on the mount (or anywhere on the lens), is there a way to still tell when the lens was mfg?
I noticed that all the lens that i have seen are mfg at Utsunomiya ( U = Utsunomiya, Japan)
none from F = Fukushima, Japan
O = Oita, Japan
anyone knows why?