Most of our binoculars bend at the body hinge to move the eyepieces closer together or farther apart, in order to match the eyepiece spacing to your own eye spacing. To find the perfect IPD setting for your eyes, view through the binocular at a distant target, and flex the binocular hinge until you notice the “sweet spot” of one well-merged circle in your peripheral vision. Don’t actually look at the field stops (the black circle in each eyepiece) as you have to cross your eyes to do that- and you’ll never get the circles to merge. Note also that the field stops will be somewhat out of focus when you’re looking at a distant target, so simply look for a well-merged fuzzy circle in your peripheral vision.
For binoculars with a built-in mount (20×65 ED Deluxe, 20×80 Deluxe III, 25×100 Deluxe), when adjusting IPD, temporarily loosen the large knob on the top of the vertical mount post. If this knob is tight, the left side of the binocular can’t move when bending at the hinge, so only the right side will swing up or down. Loosening the knob will allow both sides to swing up and down evenly.
