Hi, First I apologize in advance if I have posted to the wrong forum for this topic, or have managed not to have found the super obvious "this has already been posted a zillion times post".... Can someone help me understand how to figure (or calculate?) the "usable" range of a fixed power scope ? e.g. - a fixed power scope with an FOV of x at 1000yds has a useable (focus) range of this to that yards... I have found many posts that are quite vague, in the tone of "a 12x will be fine for (X) yards..." But nothing that really explains the useful RANGE. Appreciate any help !