Quote Originally Posted by huddy View Post
Nikon manual focus lenses are very robust with many are still going strong after 40+ years. My oldest lens is a 28/2 AI that is at least 30 years old and it is still smooth as silk. I have a slew of MF Nikkors because I know that they will probably not wear out in my lifetime if I just do the occasional CLA treatment on them. I've bought rough user lenses that have heavy cosmetic damage, stiff aperture rings, etc., but the glass is still great and they produce great images. The modern plasticky lenses would not fare so well, especially the consumer grade stuff.

My newest Nikkor lens is ca. 1972, oldest about 1966 or 67. They range from one in 98% condition to well used with lots of shiny aluminium on the focus rings. A couple had to be disassembled for new grease. They are all in 100% functional condition, with silky smooth focus and aperture rings.
The plastic lenses are cheap crap for people who are willing to throw something away instead of having it serviced - they could have been made of metal, and still work in AF mode, but that would have been expensive.