Rifle Scopes Parallax adjustments

hydewildman

Private
Minuteman
Feb 25, 2012
9
0
37
I've heard a lot of people say that sometimes to have zero parallax the focus might be a little bit off. If the focus is on the reticle and your putting the image on the same plane as the reticle to eliminate parallax how is the image not in perfect focus with zero parallax? Sorry if the question is simple but i can't seem to find the answer.