Hi Fish, The Telrad doesn't quite work like that. You are correct in thinking that the circles are projected onto the plastic screen, but like an aircraft hud, they are only seen when you look at the correct angle. It seems to the eye that they are actually being projected in the distance. So, no there is no parallax error with a telrad. Once you have aligned the Telrad to your scope/finder it will always be pretty bang on. You just adjust your eye alignment to see the circles, then put them over the target. Easy.