El Cazador said:
The further the distance... the more the parallax affects the POI.
Not quite true.
Set your rifle(none parallax adjustable scope) on sandbags so it doesn't move using a 25yd target. Then watch your crosshairs on that target as you move your head in a circle. It'll look like the crosshairs went all over the paper.
Now move to a 300yd target and do the same test. You'll see very little movement of the crosshairs. With a 100yd target there should be no movement, if the scope is set for a center fire rifle.
The distance they set a scope to be parallax free is the only difference between scopes intended for center fire and scopes that are intended for rim fire. Center fire scopes are set to be parallax free at 100yds, while rim fire scopes are set to be free at 40yds. Any thing closer than the focus distance, suffers much more from parallax than anything beyond the focus distance.
With a adjustable objective scope that has a accurate scale for the adjustments, there should be no parallax for the range the objective adjustment is set for.
Parallax only becomes obvious at ranges beyond where the scope is focused when the magnification starts to get pretty high. For distances closer than the scope is focused at parallax is very obvious at even very low power.
Parallax is another one of those things that we can't do much about.
All scopes are free of parallax at one distance only, unless they have a adjustable objective. At any other distance they have parallax.
Even with a adjustable objective, the scope will have parallax at all ranges except the one its set at.