Adjusting for parallax

tylerevans42 said:

I currently study applied physics and have just recently learned what parallax is. While I feel that I understand it, I'm not sure how it can be "adjusted for" with a rifle scope. I have a vortex scope on my 700 and it has a parallax adjuster but I do not know how to use it effectively.

I am wondering if anybody has experience with how to use the parallax adjuster?

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Mark75H said:

You set it for the distance you are shooting.

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tylerevans42 said:

It only has adjustments from 50-100 yards but I shoot well beyond that. I thought if it corresponding to shooting length I would be able to adjust beyond 100 yards

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Overboost44 said:

Here is a pretty thorough article on the subject. Maybe it will help. http://www.longrangehunting.com/articles/what-is-parallax-1.php

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wilcam47 said:

this says 50yards to infinity
http://www.vortexoptics.com/product/vortex-viper-4-12x40-pa-riflescope-dead-hold-bdc-reticle

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wilcam47 said:

it has nothing to do with ballistic drop....just for clarity at the particular yard setting on the dial.

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tylerevans42 said:

parallax can be observed by the target appearing off center from my reticle by moving the orientation of my eye? Or my head completely?

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smdub said:

Yes. Rest the scope on a sturdy bench and point it at a nearby object (parallax is worse at closer ranges). When you move your eye side to side (or up/down) you will notice the crosshairs 'move' across the target if the parallax dial is set wrong.

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tylerevans42 said:

While keeping my head perfectly still, correct?

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smdub said:

No, move your head.

If keeping your head still, and just looking around the sight picture w/ your eyes won't do anything. Your pupil isn't moving side to side enough the TINY amount it takes to 'look around'. Plus, you're always looking right at the center of reticle when shooting anyway so that isn't a problem in real life.

When you move your head, you are displacing your pupil so that it is seeing the image more from the side, than the center. When shooting you don't typ move your head around but every time you mount the rifle, your head is in a slightly different spot each time. THAT is whats causing the problem. The parallax setting of the scope will superimpose the reticle at some distance out. This can be simulated by putting you finger up in front of your face half way betwen your eyes and monitor. Imagine this is a 50yd parallax and your monitor is at 100yds. Move you head side to side (while holding finger still) and you will see your finger 'move' across the screen. Just looking around while holding your head still does nothing. Now, place your finger right up against the monitor and repeat (both at 100yds). It doesn't move across the screen anymore does it?. Of course the scope isn't actually placing the reticle way out at your target (would take a LONG scope body) but its using optics to simulate it.

Click to expand...

smdub said:

No, move your head.

If keeping your head still, and just looking around the sight picture w/ your eyes won't do anything. Your pupil isn't moving side to side enough the TINY amount it takes to 'look around'. Plus, you're always looking right at the center of reticle when shooting anyway so that isn't a problem in real life.

When you move your head, you are displacing your pupil so that it is seeing the image more from the side, than the center. When shooting you don't typ move your head around but every time you mount the rifle, your head is in a slightly different spot each time. THAT is whats causing the problem. The parallax setting of the scope will superimpose the reticle at some distance out. This can be simulated by putting you finger up in front of your face half way betwen your eyes and monitor. Imagine this is a 50yd parallax and your monitor is at 100yds. Move you head side to side (while holding finger still) and you will see your finger 'move' across the screen. Just looking around while holding your head still does nothing. Now, place your finger right up against the monitor and repeat (both at 100yds). It doesn't move across the screen anymore does it?. Of course the scope isn't actually placing the reticle way out at your target (would take a LONG scope body) but its using optics to simulate it.

Click to expand...

smdub said:

No, move your head.

If keeping your head still, and just looking around the sight picture w/ your eyes won't do anything. Your pupil isn't moving side to side enough the TINY amount it takes to 'look around'. Plus, you're always looking right at the center of reticle when shooting anyway so that isn't a problem in real life.

When you move your head, you are displacing your pupil so that it is seeing the image more from the side, than the center. When shooting you don't typ move your head around but every time you mount the rifle, your head is in a slightly different spot each time. THAT is whats causing the problem. The parallax setting of the scope will superimpose the reticle at some distance out. This can be simulated by putting you finger up in front of your face half way betwen your eyes and monitor. Imagine this is a 50yd parallax and your monitor is at 100yds. Move you head side to side (while holding finger still) and you will see your finger 'move' across the screen. Just looking around while holding your head still does nothing. Now, place your finger right up against the monitor and repeat (both at 100yds). It doesn't move across the screen anymore does it?. Of course the scope isn't actually placing the reticle way out at your target (would take a LONG scope body) but its using optics to simulate it.

Click to expand...