Why I buy lots and lots of older, Nikon Ais lenses, and use them in the business of making photographs and videos.

There are many people who would not even consider a lens that didn't autofocus, and I can understand their position. Some have poor vision and are unable to achieve sharp focus with today's DSLR focusing screens. Others feel as though technology is the salvation and advancement of every field and every pursuit. A pervasive belief that every new generation of lenses is, logically, better than the last. And a fair number of folks just haven't been exposed to the idea that some of the finest lenses are still available in somewhat good supplies on the used market.

Photographers can be an odd breed and seem always ready to choose the "idea" that a super sharp or super fast lens is innately superior to a lens with "character." Or that there are limits to how sharp a lens has to be to make a convincing and attractive photograph. But consider this: Most lens and camera development is not aimed at making stuff better, it's aimed at making stuff cheaper to make and more profitable to sell. 

While it's true that new lens coating technologies can be better, and, as regards cameras bodies, new sensors can offer better performance but, the critical thing about making great lenses is creating a process to enable and maintain tight tolerances, parallel planarity from element to element, and to use materials that ensure both precision and long term reliability.

It seems that most lenses coming from camera makers are