Binoculars - what do the numbers mean?
First thing you notice when trying buying a pair of binoculars are these numbers - for example: 4x30 or 10x25 - what do these numbers mean anyway? - the numbers mean everything - what the binoculars can do & whether they fit your need.
Please refer to the table on the right to see recommended usage of the binoculars according to activity.
Breaking down Numbers
Example: 10x25
The First number BEFORE "x" represents Magnification
The Second number AFTER "x" represents Objective Lens
What is Magnification?
Simply put - you & I can see everything NORMALLY at 1x magnification (meaning no magnification - seeing things as they are) - so 10x means you can see everything 10 times closer to you than if you did not look through the binoculars. so the first number if you magnification of the binoculars - this is the "power" or "magnification strength" of the binoculars.
What is Objective Lens?
To understand it easily - let's compare TWO pairs of binoculars:
10x25
10x50
Both binoculars share the same 10x magnification. However, the 10x25 will be the smaller one (compact in size) as compareed to 10x50 - which will be full-sized. Objective Lens determines its physical size.
Finally Objective Lens also determine how much "light it gathers" - if you want a brighter picture - you will buy a full-sized 10x50 - however, if you want the same zoom (10x) - but want it in compact size (to fit in your pocket) and are willing to forgo image brightness 10x25 would be the right choice.
Let's put Magnification & Objective Lens together & see what happens
When you put these numbers together - you get another important attribute in binoculars - Exit Pupil. Exit Pupil is a measurement of the “hole” in millimeters where light travels through the eyepiece and into your eye for viewing.
Wanna sound like a pro - ask someone who is carrying a binoculars "whats the exit pupil on your pair?"
Before you speaking "jargon" - let's see what this exit pupil is all about.
Exit Pupil = your objective lens number divided by your magnification number.
10x25 example: your exit pupil = 2.5mm (millimeter)
10x50 example: your exit pupil = 5mm (millimeter)
The larger the Exit Pupil - the more light is let into your eye which in turn produces brighter images. So if you are viewing images in low-light conditions - say in a brush or shadow, the larger exit pupil binoculars will be a better choice.
Hope the above information helps you choose your pair of binoculars - and why settle for one pair - when you can get multiple pairs - with our daily deal prices? - so come back often - and buy a few!!
Happy Shopping!!
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|  | Binoculars/ by usage
| Activity/Adventure | Recommended Binoculars zoom/type |
| Bird watching | 8x42 is the standard, 10x42, 10x50 & 12x50 for
Details in Smaller Species at a Distance,
Compacts with a 30mm or Greater Objective Lens size,
Any Binocular with Long Eye Relief and Good Close Focusing Ability |
| Boating | Any Waterproof Model with A Large Objective Diameter and Rubber Armor,
7x50, 7x42, 8x42 & 10x42 |
| Concerts/Theater | 5x25 & 8x25 Xtra-Wide Angle, 4x30, 7x18 & 7x21
Compacts, Any Zoom or Wide Angle Model |
| General Use/Vacation/Hiking | 7x35, 8x42, 10x42 & 10x50, Most Compact and Wide Angle Models |
| Hunting | All Rubber Armored, Waterproof and Fogproof Models,
7x to 10x Power Models for General Hunting,
12x or 16x for Distant Game/Varmints,
Compacts fit in a Pocket for Hunters on the Move |
| Low Light | 7x50 (Best Light-Gathering), 8x42, 10x50 |
| Outdoor/Nature | Any 7x35, 7x50, 8x42 & 10x42 Standard Size, 8x30 & 10x30 Compacts, Waterproof Models for Camping |
| Sports /
Stadium Sports | 4x21, 8x25 & 10x25 Xtra-Wide Angle, All 7x35, 10x50 & 12x50, Any Zoom, Compacts from 7x to 10x |
| 10x50 Binoculars with Ruby Red Coated Lenses PLUS 4x22 concert binoculars
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| | | 10x50 binoculars feature ruby coated lenses for greater glare reduction and rubber eye cups for additional comfort. Also come with neck strap and carrying case. Barrels measure 6' in length. Concert binocular barrels measure 3-5/8'. Limited ten year warranty. Clam shell.
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