Quote Originally Posted by benjiboy View Post
The point I was trying to make about comparing lenses in general and particularly twenty five year old lenses is that we don't know how each example would compare with the other ones initially on test when they were manufactured , and after twenty five years of being kept and used in different manners in different parts of the World probably by several different owners my FD 24mm f2 optic might give very different results to another example of the same lens that somebody else has thousands of miles away in in a very different climate.
The point I was trying to make was that a well-built lens normally shouldn't suffer after 25 years of (non-destructive) use in any part of the world.

As I previously mentioned, with the very many brands I've used, time has little effect on lens performance, unless affected by haze, fungus or physically damaged or worn out (rare).