Carson Optical Binoculars - Manual (Page 6)

Focusing your binoculars:
Most binoculars have a center focus wheel and an independent right diopter eyepiece to account for
small differences in the strength of each eye. Please follow the steps below to focus properly:
1. Adjust the interpupillary distance.
2. Rotate the right eyepiece to its index mark and sight on a fixed distant object.
3. Cover the right objective (front) lens with your hand, then rotate the
central focusing wheel until the image in the left eyepiece is sharp.
4. Cover the left objective (front) lens with your hand then
rotate the right eyepiece until the image is sharp.
(Note this setting for future use.)
5. Image should now be focused to
your individual eyestrength.
Please note that certain binoculars have
different focusing systems. Some may
only contain a center focus wheel which will
focus both eyepieces simultaneously. Some may employ
a central focus wheel with a rotating left eyepiece.
central focusing wheel
roll-down/twist-adjust eyecups
adjustable
right diopter
(eyepiece)