what is this paralax you speak of?

[ironman5669]

can someone please explain what paralax is? i am new to using optics and it keeps coming up.

[SanPedroShooter]

http://en.wikipedia.org/wiki/Parallax

Just a primer. scroll down to the bottom. Parallax in small arms
there's different kinds of parallax

[bruce_ventura]

In the link above go to the section labelled Parallax and measurement instruments. Telescopes optics relay the image of an object located at some specific distance, say 100 yards away, onto an image of the reticle so that both are superposed and in focus. As long as the target is at 100 yards, the reticle is locked onto the target and does not shift even when the shooter moves his/her eye left or right. If the target is at some other distance, say 50 or 200 yards, then the reticle appears to shift across the target when the eye moves left or right. This is called parallax. A scope with an adjustable objective (AO) allows the shooter to focus the reticle to any target distance so that the reticle doesn't shift.
However, if you train yourself to keep your eye centered in the scope field of view, the reticle will stay fixed regardless of the target distance. An adjustable objective is not essential to eliminating parallax, but it helps, especially with high magnification scopes.

[ironman5669]

ok, and thanks for the info. now on to specifics. If I have a 4 to 12 power adjustable objective scope on my rifle, and it is focused on the center of a target at 100 yards, at 4 power, and I then change my magnification to twelve power, A) would my sight picture still be focused, and B) would my cross hairs still be on the same spot on the target? assuming everything is working properly of course.

[Mute]

On a quality scope, change in magnification should not shift the reticle plane. It should stay consistent for the correct distance adjustment.

[ironman5669]

what is the reticle plain? is that the same as saying crosshair allignment?

[Corbin Dallas]

what is the reticle plain? is that the same as saying crosshair allignment?

Plain = Bland

Plane = Flat or level surface


Reticle plane is the Z axis when you zoom in.


x = left to right
y = up and down
z = in and out

Go back and re-read what Bruce posted. No need for me to repeat it.