Rifle Scope Parallax For Dummies

rifle parallax

Diagnosing parallax–a lesson from Lucid Optics

I’ve been fortunate to attend the Blue August gun writers’ conference this week. In the process of learning about new products industry reps were there to promote, I also learned a few things about shooting. This one will be of interest to anyone who uses a magnifying scope. It was shared by Jason Wilson, founder and CEO of Lucid Optics, based in Riverton, Wyoming.
The correct definition of parallax involves more science than I can digest in a year. So here’s the Parallax for Dummies version: when viewing a target through multiple lenses, its real location may be different, by a few inches or even more, as compared to how it’s perceived by your eye.

parallax adjustment

Long range accuracy requires resolution of parallax. The rifle Savage’s BA Stealth in 6.5 Creedmoor, fitted with a Bushnell tactical scope.

A brief demonstration of parallax can be done right now. Put your hand in front of you, making a “V” with your thumb and forefinger. Through the bottom of the V, view an object across the room, like a doorknob. Focus on the V. Now, shift your focus to the doorknob. Notice how whatever you’re not primarily focused on appears to float a bit? Perhaps a duplicate image even appears.
Our eyes are incredible tools, and so are good quality scopes. But this bit of inaccuracy could result in a miss or an inhumane kill, so it must be addressed by the long range shooter.
antelope_kill

Fine-tuning your scope to your own vision is necessary to achieve a humane kill. Photo by Lucid Optics

Now that you’ve witnessed parallax sans scope, let’s diagnose it behind the glass using Wilson’s technique. This method assumes your scope is securely mounted to your rifle and zeroed for you, not some other shooter.
Make sure the rifle is supported on a bipod or other object and is stable. Pick a stationary target at midrange distance, about 300 yards. Make sure the picture is clear and in focus as you center the reticle on it. Now, keeping the rifle and scope perfectly still, move your head, keeping focus on the target. See how the target appears to move around? Repeat this head movement exercise, taking note of whether the reticle stays on the target and appears to move with it, or whether it remains in the center as the target “moves” around.
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Shooting with the magnification of my L7 scope at a recent event. Photo by Kirk Wheeler

If the center of the reticle remains on target, moving in unison with it, you’re good to go. If the reticle and target separate, you’re experiencing parallax.
Wilson said that many people make the mistake of assuming the left-hand adjustment knob on their riflescope (if one exists) is a fine focusing knob. It’s actually there for parallax adjustment. If your scope has a parallax adjustment knob, repeat the parallax test as you continue turning it until the target and reticle images “float” as one.
rifle parallax

Parallax is less likely to occur at short distances. Pictured is a recent test of Huber Concepts’ trigger and muzzle brake.

Incidentally, the fine focus adjustment on most riflescopes is the small ring on the very rear of the optic, behind the magnification adjustment. My long-range shooting advisors recommend securing that ring with electrical tape once fine focus is achieved for you and your scope. That prevents unintentional turning of the ring as you carry the rifle afield.
the_lucid_l5_scope_viewed_from_the_right_side-_the_focusing_ring_can_be_seen_on_the_far_left

Lucid L5 scope pic is by Lucid Optics


As the owner of a Lucid Optics L7 scope, which was previously reviewed on GunCarrier and held up to some hard use over the summer, I was eager to meet the man behind the optics. It was a treat to take in a bit of Jason Wilson’s encyclopedic expertise on optics and their human interface. My scope doesn’t have a parallax adjustment, by the way, but Lucid Optics’ L5 models, with more magnification, do.

4 Responses to :
Rifle Scope Parallax For Dummies

  1. jumpoffa says:

    Now that is a great tip.

  2. Hairr says:

    I think that breaking in your Building was a sick thing to do ,and because you know that saying What Comes Around Goes Around!!! When you do stuff like this to People then You Reap What You SOW God Don’t Like Ugly!!!! The reason I’m Saying this Stuff Are to Let You Know Someone Broke In And STOLE MY GUNS!!!!!!!!!! I’m Still MAd As HELL!!!!!!!

  3. Ken jelinek says:

    What if I don’t see a flouting object or moving

  4. Rick says:

    Thank you for clearing the issue up for me. You explained it in plain English as well 👍

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