[Jack]

I sold binoculars for a number of years. Everything from 29.95 Bushnells to Leitz.
One thing that struck me, and I saw it constantly, was an enormous difference in people. Some people could literally look thru 29.95 cheapies (and, oh, my they were cheapies) and then a 200+$ binocular, or even Leicas- and they couldn't tell one from the other. Honest. I did blind tests with people many, many times.
Does that mean the binos were similar in performance? NO! Believe me, they weren't.
I saw other folks that could look through a mid/upper level binocular and immediately see any flaws. And this was with blind testing- they had no idea what brand they were looking through.
I don't know the proper term, if there is one, but each individual's visual acuity, or standards, or something, is quite different.
Something to keep in mind.