What is parallax?

[Lightsped]

I am new to scopes and optics. I bought a scope with a parallax correction adjustable objective.

Today I went to the range and tried shooting at various ranges to sight in my scope. Once the scope was sighted in, I turned the parallax to a close range distance and fired several rounds. Next I remained in my previous spot, and turned the parallax to a long range setting and fire a couple rounds.

All of the rounds went in the same location on my target. The parallax adjustment didn't seem to change anything.....

Can anyone help clear this up for me, as obviously I don't have as much knowledge about optics and parallax I should....

 

[Dave P]

Not an explaination, but a how-to:

Mount rifle in a stable base, like sandbags. While looking thru the scope at a far target, move your HEAD ONLY around a bit. Don't touch rifle or scope.

Do the crosshairs stay exactly on target? Prolly not.

Adjust parallax knob until they do - now you are set for that distance. No matter where your cheek rests, the crosshairs will show where the impact will be (assuming you have adjusted windage and elevation for POI).

 

[rcmodel]

Parallax is the apparent movement of the reticule on the target when you move your eye around behind the scope.

All scopes have it, and the AO on your scope allows you to set it to be parallax free at the range you intend to shoot.

Scopes with high magnification say above 12x are very critical that you either place your eye exactly in the same place each shot, or else adjust the AO for the range. Otherwise, a very tiny group can easily become a very large group if you move your eye around.

It's not so critical at low power and hunting scopes below 9 or 10x usually are adjusted at 150 yards or so to be parralax free. Up close error isn't enough to miss a deer, and beyond 150 or so, paralax is not an issue because the scope is focused to infinity.


rcmodel

 

[Lightsped]

Wow, thanks for the explantions. As shown, I had no clue what I was talking about.... Next time I am at the range, I fiddle with the parallax adjustment and move my head around a bit to see what you guys are talking about.