Lately, I’ve been experimenting with a couple of scopes from Bushnell; one from their Elite Tactical line, and the other one is a lower powered rimfire optic. An interesting feature on both of these scopes is the parallax compensation adjustment.
I don’t usually prioritize this feature as a must-have in the scopes that I buy, but I can understand why some people like it. In discussing the issue with other shooters, I’ve found that there are some common misunderstandings not just about parallax adjustment, but about scope parallax in general. I think that’s at least partly due to the fact that the concept of parallax is often explained in an overly-technical way that many people either find confusing or boring.
Fortunately, you don’t actually have to wrap your head around all of the technical details of parallax in order to have a basic understanding that’s sufficient enough for most shooters to make adjustments for it. Compare it to something like bullet drop — I don’t have to know how to calculate the constant of gravity versus the bullet’s velocity and mass and the curvature of the earth in order to know that when I shoot my .308 at 200 yards with my favorite factory ammo, I have to hold about 3.5 inches high.
So in today’s video, I’ve taken my best shot at explaining what rifle scope parallax is for the average shooter, as opposed to someone who wants to make a career in optics manufacturing.
What is Rifle Scope Parallax? Watch the Video:
Parallax in Plain EnglishHey, guys. Chris here from Lucky Gunner. And this is my very best attempt to explain rifle scope parallax in plain English. So let’s say you’re sitting behind a rifle on a bench. It’s completely supported. You’re not touching it all. And you look through the scope. The crosshairs are perfectly centered on the target. And then you move your head around, and the crosshairs appear to move a little bit in relation to the target. That is parallax. It happens when your eye and the target and the lenses in the reticle inside the scope are not all perfectly aligned, usually because your eye is not exactly centered on the eyepiece. So the result is that to you it looks like the crosshairs are aimed at one spot, but they’re actually lined up with a slightly different spot. So when you fire, your bullet doesn’t go where you expected it to go. Even if you shoot with optics a lot, you may not have ever noticed any problem with parallax, and that’s for a couple reasons. The first is because most scopes are set up to be parallax-free at a specific distance. Usually it’s 100 yards. If it’s a rimfire scope, it might be 50 yards. So at that distance, you’re not going to have any parallax. You move your head around all you want, and the crosshairs should not move in relation to the target. Reflex sights are parallax-free at all distances. So if you always shoot with the red dot, you’re never going to have any problems with parallax. The other reason you may not have ever noticed any problem with parallax is because the margin of error is usually really small. With the run-of-the-mill three- to nine-power scope, at distances up to about 500 yards, your maximum parallax error is probably going to be less than an inch. So it’s more of an issue if you’re after super-precise shooting, or if you have a scope with really high magnification, over about 12 power, or if you’re shooting at really close ranges, maybe under 25 yards. There are ways to compensate for parallax. You can use a scope that has a parallax adjustment, like this knob here, or it might be up here by the objective lens. And you just set it for whatever distance you want. Usually there are hash marks on here, and they’re kind of a rough guide. But when you get it set up the way you want, you can basically set it to be parallax-free at whatever distance you’re going to be shooting at. Another way to adjust for it is just to make sure your eye is centered on the eyepiece. And the way to do that is to back your face off from the scope a little bit so you can see the black of the eye piece all around your image. And just make sure there’s an equal amount of black all the way around. This is where a good consistent cheek weld can really come into play. And a good cheek weld is usually a lot cheaper than buying a scope with a parallax adjustment. So that is my quick and dirty parallax explanation. I hope it makes sense.
If you’re the average hunter or if you’re just shooting at the range for fun, then you probably won’t have to worry about parallax too much. But if you’re after extreme accuracy with high magnification scopes, or you’re shooting at super close ranges like a lot of competitive air gun shooters, then it’s something you should know about and consider when you’re buying a scope.
