When a PGA Tour player must know the distance to the pin, he asks his caddie, who carries a yardage book with details about each hole, according to PGA caddie Mark Long. When a casual golfer needs distance information, he must use a yardage marker and add or subtract yardage based on a visual estimate. PGA pro Mark Blakemore, however, notes that yardage markers identify the distance to the center of the green, not to the pin placement. Range finders send laser or infrared light to the target and back and are accurate to within 1 yard, according to manufacturers. To test a device for accuracy yourself, use the following instructions, which are based on user manuals of popular brands.
Find a target at a known distance. Try a driving range, where distance flags are set directly ahead of the tee boxes. Alternatively, use any two points which are a known distance apart. For example, go to a high school football field and stand in the middle of one goal line. The opposite goal post’s crossbar will be exactly 100 yards away.
Press the power button to turn on your range finder to begin the test.
Look through the binocular or monocular lens and locate your target.
Lock your device on target, according to the manufacturer’s instructions. There will be some type of aiming device, such as a circle or crosshairs, that you’ll aim directly at your target. Then you’ll typically push a button to transmit the laser or infrared light. Some Bushnell models, for example, use a circular aiming device and require you to push the power button when you're locked onto the target, according to the company.
Read the distance measurement on the range finder’s screen. In a Leupold device, for example, the distance appears at the top of the screen, according to the company's user guide.
Compare the displayed distance to the known distance between yourself and the target.