How to Focus Binoculars
AMC Outdoors, May 2004
By Michael Lanza
Vision can vary between your two eyes, and consequently most binoculars allow you to adjust the focus for each eye with the help of a "diopter setting ring." Just follow these simple steps:
Adjust the binocs to match the distance between your eyes.
Keeping both eyes open, view a distant object.
Using a lens cover or your hand, cover the objective lens located on the side with the diopter setting ring (normally the right lens).
Using the focus adjustment (which changes the focus for both eyes), bring the distant object to maximum sharpness.
Cover the other objective lens, then view the same object.
Using the diopter setting ring (which only focuses the one side), adjust the image and bring it into clear focus. The setting ring is usually located close to your face, typically on the eyepiece.
For zoom binoculars, adjust the focus at the highest power setting.
Your binoculars should now be adjusted for your eyes.
—Michael Lanza is author of The Ultimate Guide to Backcountry Travel, from AMC Books.
