To answer that, I'll refer back to information shared during a Nikon seminar. The lens "recipes" are unique to Nikkor lenses. Each element within the lens assembly may or may not contain the exact same recipe for the glass making up that element. Each element is custom-tuned to its place within the assembly for which it's made. The other lens manufacturers don't go to that extent. Thus, Nikkor lenses do a lot better job of focusing, removing aberrations, etc. than their competitors. So, my approach has always been Nikon glass for my Nikon cameras.
--Bob

I don't like mysteries. Since getting a new stove, I have a mystery. The stove is one of those black, flattop units. Unfortunately, not all of my pots have a perfectly flat bottom. They have a raised center, as if someone hit them from the inside with a ball peen hammer. When I put a pot of water on to boil, the pot will begin to rock back and forth rhythmically at the rate of several times a second. It will start doing this as soon as the water gets hot. It doesn't have to be boiling. I can stop it, but it will start up again. Why does this happen?

A mystery I solved - Did you ever notice the smell of rain? Occasionally, when it begins to rain, I know it's raining because I can smell it. I did some research and discovered that the smell is called petrichor, a fairly new term.

https://en.wikipedia.org/wiki/Petrichor

My horse gets "hot" shoes while the other horses on the ranch just get trims. In short, hot shoeing insures a better fit than when the shoes are merely pounded into shape without heating them. The farrier (shoer) places the heated shoe, which has been pounded into shape while it's glowing red, against the trimmed hoof and can tell from the seared mark whether more hoof trimming and/or shaping of the shoe needs to be done. The process creates quite a bit of smoke. Stinky smoke. Think burning hair smell.

The last shot shows one side of the "shop" that is hauled behind the farrier's truck. Some farriers have the setup mounted on the truck bed, but this fellow likes to use his truck for other things.

In some of the shots you might get an idea of what backbreaking work this is - even when the horses cooperate! It's worth every penny to pay the pros to do the job.