I'm not really "passionate" about this topic. It's simply a matter of logic. Your camera lens and your enlarger lens are your two most important pieces of equipment. They will leave their mark on every image you take and print. Having said that on the 35mm end the no nonsense new mint leave-no-doubt-in-my-mind lens costs $40 typically... and can be had for $5 rarely. So the question is why even think about it? If you want to see "passionate" start a thread asking whether APO lenses are "worth it." Bring an asbestos suit though!
Originally Posted by ChristopherCoy
The lens I was referring to is the El Nikkor 50mm 2.8 N. That is the latest model I'm aware of... I stopped looking after I got mine. There is an older non "N" version.
In addition to lens design other things such as fungus, dust, and haze (from dark room vapor etching) can degrade lenses with time. That's another reason I went for a late model lens. Although even the N version has been around for quite some time.