Comments on: Binocular..what does it mean?

By: CIH(Ret)

CIH(Ret) — Sat, 08 Dec 2007 17:39:08 +0000

The first number is the power of the binoculars and the second number is the diameter of the objective lens in millimeters. So a binocular that is listed as being an 8 X 40 is an 8 power binocular with 40 millimeter diameter front lens. The larger the front or objective lens is, the better the ginocular is at gathering light. this applies only when your are comparing like binoculars. Some of the high end binoculars have very high quality lenses with some very high quality coatings on them. these lenses will gather more light than an equil size lens of a lesser quality. This is the reason that you get what you pay for when you are buying optics.

One thing to bear in mind is that as the power goes up on a pair of binoculars, the harder it is to hold them still enough to get a clear view. The higher powers exagerate the natural shake of your hands. Most people are limited to no more than 8 power binoculars because if they go to 10 power, they have to use a tree or something to steady their hands enough to see through them. Other people can handle the 10 power binoculars okay. Just be sure to try them out before you buy them so you know if you can hold them still enough to see through them. Even better, if you have a friend who has some binoculars like you think you’d like to buy, ask if you can borrow them for a day to try out. Take then out with you on a hike and give them a thorough tryout by looking at birds. scenery, etc. If you can afford them, there are some out there that have image stabilization in them but they ain’t cheap.

In the end, decide what is the most you can spend for binoculars and then buy the next better ones.

By: JD

JD — Thu, 06 Dec 2007 07:54:48 +0000

Stampy Skunk nailed this one. His answer is detailed and correct, and obviously came from first hand knowledge, not quoted from outside source reference materials….

By: Stampy Skunk

Stampy Skunk — Tue, 04 Dec 2007 22:04:30 +0000

First - Magnification

Second - Size of the outer lens in millimeters, the lens you are not looking through….. it is better to get binos with a larger lens size, the larger the lens the more light it lets through and the better picture and field view you have, so it would be better to get a pair of 10X40 versus 10X25……. the 40mm lens lets in more light.

For long distance you would get binos with a higher first number, example…. 16X40 can see farther objects than a 8X40 set. 16 times the magnification.

By: jasonbatla

jasonbatla — Sat, 01 Dec 2007 18:19:59 +0000

First# is for magnafication,2nd# is how wide the large lens is in millimeters 8X40 is a good all around bino

By: Ben Dover

Ben Dover — Sat, 01 Dec 2007 00:09:32 +0000

The first number is the magnifier number, how much it magnifies what you are looking at. The second number is the size of the lens.

From Consumer Reports:

“Decide on what power you need. Power represents the number of times an image is magnified by the binoculars. Most common for outdoor uses like bird-watching and hunting are 8x and 10x–the powers we rated for this report. Higher powers like 20x and beyond are preferred by astronomers, while 7x is probably sufficient for sports spectators and theater-goers.

Choose a lens size. You also need to know the diameter of the binoculars’ objective lenses, represented in millimeters by the second number in binocular measurements (such as 8×42). Larger lenses allow more light to enter and provide a better image, but can also be heavier.”