Before laser rangefinders were common place in the hunting world, bowhunters had to rely on their ability to judge distance on the fly. Fortunately, todays archers not only have access to rangefinders but models that read and automatically adjust for angle. These modern rangefinders contain small electronic processors that run a complex calculation in less than a second and tell you what yardage to shoot. But can you trust them?
Before we can answer that question we have to first look at angle compensation in closer detail. When a rangefinder gives you a line of sight distance to a target on flat ground, that distance and the horizontal distance are the same. Add elevation to the equation and things begin to get interesting. As the elevation of either the shooter or the target increases or decreases the line of sight distance increases while the horizontal distance stays the same. In shooting, no matter the weapon, it is the horizontal distance that should be used when aiming. Meaning when shooting at an incline or decline you should aim low or use a sight pin for a shorter distance than the line of sight distance.
Through personal experience using multiple angle compensating rangefinders in steep terrain, I can personally attest that the technologies they use are accurate, but not perfect. I’ve found that regardless of angle compensation, shots at 20 degrees or less show little difference in point of impact inside of 40 yards. Once distance and/or angle is increased the gap between line of sight and horizontal distance becomes significantly wider, making an angle compensation rangefinder nearly invaluable. With that said, practicing steep angled shot is a must if you plan to hunt in areas with lots of elevation change.
Editor's note: This was originally published in 2016.