Interpupillary (Interocular) Distance
Since the distance between the eyes (specifically, the distance between the
centers of the pupils) varies among individuals, the two eyepieces of the
binoculars must be correctly aligned. This is called adjusting the interpupillary
distance.
To adjust this distance, begin by setting the diopter eyepiece to 0. Lift the
binoculars up to your eyes and look through them. Move the two halves of the
binoculars about the hinge until you see one clear circle of image.
Eyeglass wearers should roll down the rubber eyecups to obtain the maximum
field of view.
Adjusting Focus
Since most people have a variance in vision from their left eye to their right, you
must adjust the focusing system. Use the following steps to achieve focus:
1) Close your right eye and look through the left side of the binoculars with your
left eye at the subject matter. Rotate the center focusing wheel until the image
appears in sharp focus; 2) Close your left eye and look through the right
eyepiece. Rotate the diopter (right) eyepiece until the image appears in sharp
focus; 3) Now look through both eyepieces with both eyes open. Since you’ve
already adjusted the right eyepiece, use only the center focusing wheel to
refocus on a new object at a different distance.
Now, attach the binocular strap (if you have not already done so) and you can
begin using your Celestron binoculars.
Care and Cleaning
Binoculars do not need routine maintenance other than making sure the
objectives and eyepieces are clean. If repairs become necessary, they should be
serviced by the manufacturer or a qualified binocular repair company. Collimation
(optical alignment) is the biggest concern with binoculars. If your binoculars are
roughly handled or dropped, there is a good chance that the collimation will be
out and they should be serviced.
Dirty objective lenses and/or eyepieces mean less light transmission and loss of
brightness as well as unsharp images. Keep your optics clean! When not using
your binoculars, keep the lens caps on (when provided) and store them in a
case. Avoid touching the glass surface, but if fingerprints (which contain mild
acid) get on them, they should be cleaned as soon as possible to avoid
damaging the coatings. To clean the optical surfaces, we recommend a
lens/optics cleaning kit available at most photo stores. If you have multi-coatings
there are special cleaning kits especially made for these. If you have a lot of dust
or dirt accumulated, brush it off gently with a camel’s hair brush and/or utilize a
can of pressurized air. Then use the cleaning kit.
