Night Optics Falcon 6x Gen 3 Gated Long-Range Night Vision Binocular - Manual (Page 107)

2-72
NOTE
The sharpest image will be observed only when
the objective lens and both eyepiece lenses are
properly focused.
(6) Fold the right eyecup over the eyepiece lens with your
right thumb or forefinger to obstruct view through the right
eyepiece lens. Rotate the left diopter adjustment for the clearest
view of the image intensifier screen.
(7) Fold the left eyecup over the eyepiece lens with your left
thumb or forefinger to obstruct view through the left eyepiece lens.
Rotate the right diopter adjustment for the clearest view on the
image intensifier screen.
(8) Adjust the eye relief distance by pressing the eye relief
adjustment (Figure 2-13) and sliding goggles fore or aft to obtain a
full field-of-view of the image. Reset the diopter adjustments for
best image.
NOTE
Any readjustment of eye relief requires resetting
the diopter adjustments.
(9) Adjust the objective lens focus (Figure 2-1) while
observing an object until the sharpest image is obtained.