I have a Leupold Vari-X 3 bought sometime between 1995 and 2001. I don't understand these Yards/Meters markings on the zoom ring as depicted below. Can you shed some light?
That was designed as a rangefinder. I can’t remember exactly how it worked but it was along these lines:
Square the body of a deer in the reticle using increasing/decreasing magnification. When the plex reticle measures back to belly, the yardage indicator lets you know approximate distance. I think that’s for Whitetails.
It's a specific distance in yards where the reticle brackets a set amount of inches. I don't know the exact amount, but it's something like this. The space between the center crosshair and the heavy post of the reticle might be 15 inches. That 15 inches is accurate at the distance in yards marked on the zoom ring. It's kind of a crude way to range find. Kind of an irrelevant method today with the availability of accurate electronic rangefinders.
AHA! Further googling of the concepts you shared above led me to the term "subtension rangefinding", which. . . well, which just explains the same thing you guys just explained.
It's designed for range finding. Center of cross hair to bottom where the line thickens is for whitetail and top to bottom of fine lines is for elk. Don't know how accurate it is but that is Leopolds description. I have an old scope with the same thing.