How to Focus & Test Binoculars

How to Focus Your Binoculars

Most binoculars have a central control that focuses both barrels at the same time. They also include a “diopter” adjustment ring to focus one barrel independently, allowing you to compensate for differences in vision between your eyes.

If you’re wearing glasses, start by rolling the eyecups all the way down—or twisting them all the way down—before you begin.

To focus your binoculars, do the following:

1. Cover the right* lens with a cap and sharply focus the center control on a distant object.

2. Switch the cap to the left* lens and sharply focus the diopter control on that same object.

3. You’re done; leave the diopter as is and use the center control for all focusing.

*If your binoculars have the diopter on the left lens, reverse where you place the lens

How to Test Out Binoculars

To get a sense of focusing ease, how comfortable binoculars feel in your hands and their optical clarity and brightness, you need to visit a store where you can try out several of the models you’re considering.

If the retailer doesn’t have a test chart to view, then focus on a detailed object across the store. Pay close attention to the overall sharpness and brightness of the image, as well as the consistency of clarity and brightness from side to side in your field of view.