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Understanding Binoculars Magnification Numbers

At some point in life, we all choose a hobby or activity we can do while we unwind. Whether football, music, art, or even hiking. It might also be taking a walk to view the wonders nature has to offer. For some, the best way to unwind usually entails getting away from this world and taking a step through the galaxy, without really leaving planet Earth. There is always an easy way to make a spacewalk or a long nature walk, without moving an inch or in the comfort of your reclining lounge chair. It is by using a pair of astronomy binoculars.

The human eye is marvelously adapted to sense color and reacting to light, whether brightness or darkness. Our brain acts as the supercomputer to analyze data from our left and right eyes and merges it into one perfect view. Astronomy binoculars harness the power of the brain into focusing on the single task spacewalk and enjoying its marvels. If you are new to this, choosing the best binoculars for stargazing can be a tedious task. There are so many binoculars ranges and specs to choose. Add the terms and numbers, and it now turns in rocket science. Today we will try to understand the binoculars magnification numbers.

1. Size

Astronomy Binocular Size

Binoculars come in different sizes. The full-sized with common specs of 8 x 42, 10 x 50. These are mostly perfect for use on the boat or while viewing moving objects like birds and wildlife. They can capture more light hence make them perform better in low-light situations. This is also the best astronomy binoculars option. The relatively steadier images and wide field of view make them suitable for viewing wildlife and birds too. On the flip side, they are big and bulky for backpacking.

Mid-sized with common specs of: 8 x 25, 10 x 25. A bit heavy, but balance moderate size with above-average light transmission. They are good for sports.

Lastly, we have the compact with common specs: 8 x 25, 10 x 25. These are the smallest and lightest varieties.

2. Binoculars Magnification Powers

Astronomy Binocular Power

All binoculars have two numbers written on the back. These numbers are used to differentiate the power of the binoculars. Earlier, you saw numbers such as 8 x 42 used extensively. The first number, including the ‘x,’ say 8 x, represents the magnification power. This means the object will appear to be eight times closer than they are to the naked eye. For example, if something is 160 yards away, will appear to be only 20 yards away, (160 divided by 8).

3. Objective Lens Diameter


Another number used to identify binoculars is the actual lens diameter. It usually measured in millimeters. The objective lens is the lens closer to the image and farthest from the eye.

It greatly determines how much light the binoculars will be able to gather.

If you have, two similar specs binoculars but with different objective lens diameter, the only difference will be on image light quality. The one with a more significant diameter number will have a lighter hence brighter view.

4. Exit Pupil Number

Binocular Exit-Pupil

This number indicates the level of brightness of an image appearance when viewed in low-light settings. A higher exit pupil, therefore, equals a brighter image. It also makes it easier to maintain a steady full image of objects if you have shaky hands. The number is calculated by dividing the second magnification number by the first, for instance in 8 x 42, (42 divided by 8 = 5.45). Therefore, 5.45 will be the binoculars’ exit pupil number. Ideal astronomy binoculars would be one with a higher exit pupil number. In the dim light, the pupil can widen up to7mm; in this regard, the best astronomy binoculars would be one with 5mm or higher.

The above numbers should be a bright start to get to know the best way to choose the best binoculars. Whether it is for sports or bird watching, or you prefer to get astronomy binoculars for stargazing, these are the numbers to focus on before making your choice.

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