I've never been unhappy with my older Nikon 50mm lenses, and the Zeiss 50mm lenses are fantastic and have been for years. What I'm really happy with on newer l

I've never been unhappy with my older Nikon 50mm lenses, and the Zeiss 50mm lenses are fantastic and have been for years. What I'm really happy with on newer lenses is technology like fresnel lens elements that allow us to have compact and light weight telephotos. I have a Nikon 300mm lens that weighs 1/5th of its predecessor (which I also have) and is 1/3 the length and takes better photos. It was well worth the price tag and I greatly appreciate this sort of technical improvement if it allows me to avoid carrying a tripod for birding.