The Binoculars Buying Guide for 2016

When Buying Binoculars, Who Has The Time To Research All The Specifications?

At, we want to make it easier to purchase the right binoculars to fit your needs. Product details for a very popular brand of binoculars are explained.  These features represent the most common specifications provided when buying binoculars.

binoculars buying guide


When buying binoculars, keep in mind that the heavier the binocular, the harder it is to hold them steady or carry for long periods of time.


There are a range of sizes when buying binoculars, varying from mini, compact, mid-size, full-size, big and even giant binoculars.

Eye Relief:

The actual distance images are projected from eyepiece to eye, and measured in millimeters. As power increases eye relief decreases.  Low eye relief under 10mm requires that you to get very close to the eyepiece.  High eye relief (typically more than 15mm) for larger distances and is an important feature for eyeglass wearers buying binoculars. Allow at least 15mm for glasses.


Waterproof binoculars are specially sealed with rubber “0” rings and purged with nitrogen (injected through the seal). This keeps out water and moisture as well and also dust and sand. When moving from a cool to warmer environment (air conditioning to outdoors), the inside lenses will fog, just like eyeglasses without waterproofing.  This is a must have expense when buying binoculars.


Magnification is the power and is the first number in a binocular name. This number represents the number of times closer an object appears than viewed with the naked eye. For example, objects observed through 8×40 binoculars will appear 8 times as large.  The larger the magnification, the more details can be seen.

Objective Lens Diameter:

The binocular’s objective lens forms the light gathering power of a binocular and is the second number in a binocular name.  It represents the diameter of the lens at the end opposite the eyepieces and is measured in millimeters. As the objective lens increases, the size, weight and usually brightness of the binocular increases.

Field Of View:

The width of the image you see while looking through a pair of binoculars.  The number is represented as feet per 1000 yards.  More surroundings can be seen with a wider field of view.

But there is a trade-off, when buying binoculars.  The more you can see, the more your ability to distinguish details will lessen.

Exit Pupil:

The amount of light rays coming from the binocular to your eye.  Exit pupil diameter is estimated by dividing objective lens by the magnification.  The larger the exit pupil, the more efficiently the binoculars will work in dim light and the better the resolution.

Focus Type:

The focus type is the focusing systems used in binoculars.

Center Focus                         – Uses a centrally located focusing mechanism

Individual Eyepiece Focus  – Each eyepiece must be adjusted separately

Close Focusing Distance:

The minimum distance from an object before you can bring that object into focus.

Prism Type:

Prisms sort out the image so it reaches the eye in proper orientation.  There are 2 primary prism types:

Roof Prism  – straight profile, eyepieces in line with objective lenses.

Porro Prism – eyepieces set closer together than the objective lenses.

When buying binoculars, understanding basic terminology will make your shopping experience less confusing!