ACA Binoculars Page
How to focus binoculars
Common Center Focus Binoculars
To focus binoculars, begin by moving the eyepieces closer together or further apart until they are comfortable in front of your eyes and you are seeing one large round field of view. Make sure that the right eye diopter focus* is set to ZERO. Close your right eye (or obstruct your right eye's view by putting the right objective lens cover over the objective lens) and look at a distant object using your left eye. Focus the distant image by turning the center focus ring. Next, close your left eye (or obstruct your left eye's view by putting the left objective lens cover over the objective lens) and look at the same object using your right eye. Focus by turning the right eyepiece diopter ring. Once both sides are focused for your eyes, use the center focus ring to focus on objects at different distances and never turn the right eye focus again. Make a note of your diopter setting and quickly focus any binocular by turning the right eye diopter focus to your setting.
*right eye diopter focus may be located in a different location. Most binoculars have the focus located at the right eye ocular lens, some have it located as an extension of the center focus wheel.
Edited by Chris on 23/August/2005
How to hold binoculars steady
Right Handed: 1. Hold front, right side of binoculars with right hand. 2. Grab you right forearm with your left hand. 3. Lay binoculars flat on left forearm. 4. Look at star or other object. 5. Bring binoculars (and arms) up to you eyes.
Left-handed: Reverse sides.
~2002 John White
Lying down also helps steady binoculars.
You can find three (3) very good articles about binocular features and terminology at the Orion Learning Center.