What do the numbers mean on a telescope?

Answer 1

Example: 7 x 50

7 = Magnification.

The image appears 7 times bigger through the binocs than it appears to the naked eye,

giving the illusion that it's nearer.

50 = the size of the main lens

at the front of each side, 50 millimeters in diameter. The larger that lens is, the brighter

the image appears.

Answer 2

Every pair of binoculars is engraved with a formula, such as 7 x 35 or 10 x 40.

The first number in the formula is the power, or how many times the image is enlarged.

The second number in the formula is the diameter of the objective lens in millimeters. The bigger the objective, the more light can enter, and the greater the potential resolution of the image.

With hand held binoculars there is a practical limit to power beyond which it is not useful. Depending on the individual, as the power increases, hand tremor begins to degrade the image. Binoculars over 10 power usually require tripod mounting.

Answer 3

Example: 7x35

The first number is the magnification. The image will appear 7 times the size it will be with the naked eye.

The second number is the size of the objective (front) lens, which determines the binoculars' ability to gather light. This is an important issue in hunting, when they are often used at dawn and dusk, and while looking into tree lines, etc.

The smaller the first number in relation to the second number, the more light gathering. For example, a 7x20 instrument would not do as well in dim light as a 6x20, or a 7x35. A 7 or 8x50 would be even better, but at sizes above 7x35 weight and size become a factor in glasses meant for hunting.

A problem with hunting is temperature changes. Cheap glasses that are not well-sealed may fog internally, and are nearly impossible to depend on after that. A good pair of 7x35's should give you all the performance you need in the field. Plan on spending about $100 - 150 and up for a good waterproof pair. It is better to do that to begin with than to have to throw away a 50 dollar pair and then buy a good pair anyway.

And stick with name brands. You do that with your rifles and shotguns, so why get cheap when purchasing the equipment that will give you a chance to use them?

Answer 4

The numbers on binoculars represent the magnification power and the size of the lenses. This determines how far they can see distant objects and how large they will appear to the user.

Answer 5

Magnification power. 10x = the image appears ten times closer than normal.

Answer 6

It depends on what telescope and what numbers. They could be a size, an altitude or azimuth reading, or even just a model number that doesn't "mean" anything.