Just wondering about the diopter numbering scheme for the RB67 Waist Level Finder. Now I somewhat understand what diopter means. I've worn glasses most of
my life until I had Lasik done on my eyes, but I still need reading glasses, +2.0 for the computer and +3.0 for reading small print.
But the numbering scheme for the WLF diopter lenses has me confused. Are they intended magnify the viewscreen or to correct for farsightedness/nearsightedness? The ones I have seen are mostly in the -3.0 to 0 range, not appropriate for magnifying. Yet all the pics I have seen of diopter lenses are double convex lenses, therefore they are magnifying lenses and should be a positive diopter. The diopter on my WLF is -1.5, yet I seem to see ok with it. But it would seem to me that if the diopter lens is used to magnify the viewscreen they would be positive numbers yet those seem to be quite uncommon. Can someone help me with this?