Every scope and sight manufacturer has their own approach to paralax. How well do they work? Dave Merrill at BreachBangClear.com tested Red Dot Parallax for us on video.
He grabbed an assortment of red dot sights, a length of Picatinny rail, a vice, a camera, and a camera sliding rig, made a quick trip down to a local park. Using a convenient tree 68m out as a target stand, each optic was first mounted to the Picatinny rail and then mounted in the vice. Next the optic was aligned roughly to the target; being perfectly in the center of the target doesn’t matter so long as any perceived movement from parallax error could be tracked. Seeing as how the sliding rig could only demonstrate lateral parallax, the camera was squared and aligned within the upper portion of each optic window.
This gives you a great demonstration of parallax and shows how it affects different optics.
“If you’re shooting from unconventional positions without firm cheekweld, or simply using the dot incorrectly and happen to have a vantage point away from the center of the window, it may be a different story. So long as your target and your red dot are on the same focal plane, you won’t experience dot shift or will have significantly reduced shift. However, if they aren’t on the same focal plane and you get weird with your viewing position, you can experience significant deviation with your dot.”
Optics tested were the following:
- Aimpoint Micro H1 (4 MOA)
- EOtech EXPS
- Trijicon MRO
- Leupold LCO
- Trijicon RMR 01 (3.25 MOA)
- $40 Tru-Glo Walmart Special
Parallax exists. That said, it’s not all bad nor is it the end of the world–it’s just a simple fact of life. Bear in mind that parallax errors with quality modern optics are relatively small and may even require a specific set of circumstances to rear their ugly heads. With that said, I do wish more manufacturers would be up front about their claims of “parallax free”. Maybe add an asterisk and then write in really small letters at the bottom: “provided that the target is at least X meters away and then only for lateral shifts“.
Read more! Check out Merrill’s article at breachbangclear.com.