E.J.(funny, your last name is only one letter off of mine....),
Thanks for the reply.
Still a bit confused, though, on the + or - correction in the software. As in my initial example, if I use auto focus on an object, and it actually focuses an inch in front of the object, how does that inch (or whatever distance it happens to be) relate to the positive number I would enter in the software. Do I need to enter an arbitrary number to begin with, then recheck the auto-focus and if it's still out a bit, enter a different number and so on and so on until the focus is bang on? Then do this for all the points in the table (then, as you further indicate, do it again for minor corrections).
By the way, just noticed my number "eight" in my initial post resulted in a smiling sunglasses emoji. Not sure how that happened.
Marv