Binocular Magnification Chart 2021 | Step-By-Step Guide

It is defined as the ratio of objective focal length to the eyepiece focal length.  The binocular magnification sometimes represents diameters. When a person sees the objects via pair of binoculars, it increases the size of that object, called the binoculars’ magnification power.

When magnification power is more significant, its field of view decreases. A tripod is used for the stabilization of an image. This research article about the binocular magnification chart clears your mind what you think about binocular magnification.

For the high magnification, some hunters used the rangefinder binoculars, a rangefinder binoculars measured the distance from the observer to a target.

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Binocular Magnification Chart | A Comprehensive Article

The viewer chooses the binoculars with magnification that suits the situation. Mainly people want binoculars with a diameter of objective lens smaller than 25 and magnifying power 8 or 10. People use binoculars of small-size and lightweight while traveling.

formula for magnification power of binoculars

Different Magnification Power of The Binoculars

There are ten different magnification power of The best binoculars. This is a complete and comprehensive binocular magnification chart guide.

1: 7x Magnification of The Binoculars

Most people choose the binoculars of 7x magnifying power because it is used in many situations. It has a range of 3-5x.  It is the best option for the sports fan to see the ground from the seat. It produces an image that is seven times larger than the original one.

2: 10x Magnifications of The Binoculars

It is the best option for people who want to see a far distant object. Hunters use binoculars with 10x magnification because its range is longer, and it increases the size ten times larger than the original.

3: 8×25 Binoculars Range

The binocular of 8x magnification and 25mm diameter produces an inverted and large image of the object in the microscope. It gathers more light and glows up the object’s image.

4: 8×42 Binoculars Range

The binocular with 8×42 specification means that its magnifying power is 8 and 42 is its diameter of an objective lens. It increases the size eight times larger than normal and produces the sharpest image because it has a greater diameter, so maximum light is collected. It has an exit pupil of greater size

5: 10×25 Binoculars Range

Its magnifying power is 10. When a person sees through it, a clear and large image can be seen. The objective lens diameter is 25 so, it gathers maximum light and forms a sharp image. It produces a better result for magnification, sharper image, and luminous flux.

6: 8×28 Binoculars Range

When sees through 8×28 binoculars, a person sees eight times enlarge the image when sees through the naked eye. It can produce an image with the best resolution.

7: 10×28 Binoculars Range

The magnifying power of binocular is 10x, and the front lens diameter is 28mm. It is the priority of the people to get binoculars with powerful and effective results.

8: 12×42 Binoculars Range

Its magnifying power is 12x, and the diameter of the effective objective lens is 42mm. The distance of the exit pupil is 3.5mm with a 6.5-degree field of view. Its weight is approximately 840 g it can be a choice of every hiker or traveler. Its lightweight along with better resolution is demanding.

9: 20×50 Binoculars Range

When viewers use binoculars with 20×50 specifications, it produces an image of the highest quality. Its magnifying power is 20. A person can see object 20 times larger than normal. When magnifying power increases, it is difficult to produce a steady image.

10: 10×42 Binoculars Range

10×42 binoculars are commonly used for the best resolution. These binoculars are used when a person sees things in dim light. Its magnification is ten, and the effective diameter of an objective lens is 25mm. The diameter of its exit pupil is 4.2mm, and 7.6 is field view. It produces a clear and sharp image.

Understanding Binocular Magnification


  • Most people use binoculars for hunting, like, birds, elks, deers, etc.
  • Binoculars and field glasses are mostly used in the survey of vast areas and collection of geographic data.
  • Binoculars are a standard tool for game fans to see the ball and players clearly with the help of this device.
  • Marine Corps and the army both use binoculars for the field operations.
  • Binoculars are mainly used by hikers to see how far they are from their destination.

What Show Numbers in Binoculars (For Example 8×40 )

First Number| Magnification Number

In the description of binoculars magnification is the first number. For example, 8×40, 8 is the magnification number. When seeing the object from a distant place, it magnifies the object eight times greater than the original one.

Second Number| Object Lens Diameter

And the second number, (For example, 40) in the binocular explanation represents the objective lens diameter. Objective lens is used for two purposes:

It is used to find out the sharpness or resolution of the image. Furthermore, it tells about the light amount that can be collected for image formation.

What Will Happen When Binoculars of The Same Magnification Power Are Used?

When a person sees the same object with two binoculars of sane quality, same binocular magnification power, and competently same exit pupil, the binocular, which has a high diameter, produces a sharp and bright image.

For example, 8×24 and 8×42 produce an image equally eight times greater than the normal when sees with the naked eye. 24mm and 42mm are the front objective lens diameter; when the diameter increases, it gathers maximum light and produces a sharp, clear, and focused image.


The magnification power of binoculars relies upon the intended application. It is the non-adjustable and permanent character of many binoculars. It is not the feature zoom binoculars.

Optical Parameters In Binocular Magnification Chart

Before the start of the detail of the binocular magnification chart, there are some optical parameters. These optical parameters are the factors that define the binocular device and determines its performances and limits. Below is a short overview of optical parameters:


Two or more groups in the binocular eyepieces contain three or more lenses.

Field Lens

The field lens is the lens that is far away from the person’s eye.

Eye Lens

The eye lens is the lens that is closest to the person’s eye.

Kellner Eyepiece

In 1849, Carl Kellner discovered the most familiar configuration of an eyepiece. In this type of singlet and double-concave field, a lens is used. Eye lens arrangement in this eyepiece is a double convex or Plano concave doublet.

In 1975, its reverse version was invented. In this type, the eye lens is double convex, and the singlet and field lens is double concave or convex, which is a doublet. The use of the reverse type gives more than 50% eye relief.

Exit Pupil

Exit pupil is defined as the diameter of the objective is divided by the magnification. The light collected into a beam with the help of objective diameter binoculars concentrates it.

The use of an exit pupil that is equal to or the same as the pupil diameter of the human eye produces a brighter image, increased effective light collection, and increases the sharpness of the image.

The diameter of the pupil of the human eye is 3mm in the daytime and 7mm at nighttime. As age increase, this diameter decreases. A person easily puts the eye at the place where maximum light is received; it is convenient with the help of a large exit pupil.

Exit pupil is not universally standard at daytime. People use big binoculars with greater exit pupils for easy use, adjustability in applications, and comfort. These are good options for the viewers.

Field of View

When using a pair of binoculars, its field of view depends on two factors. One is magnifying power as the field of view is inversely proportional to the magnification commonly, and the second is optical design.

It tells about how many linear and angular values a person can see. A person sees the angular value in degrees and linear value in meters or feet, and its width in meters or yards.

Eye Relief

The distance between the lens of the rear eyepiece and the eyepoint or exit pupil is called eye relief. A viewer places the eye behind the eyepiece in eye relief to see the image. Potential eye relief is increased when an eyepiece of a larger focal length is used.

Eye relief is very important for the wearers of glasses. Its normal range is from a few mm to 2.5 or more cm. when the binoculars with slight relief are used, and it is hard to handle because of the face problem of keeping them straight.

Close Focus Distance

A binocular can entirely focus on the closest or nearest point, which is called close focus distance. Its value range from 0.5 meters to 30 meters. The value of close focus distance depends on the arrangement of the binoculars.

When close focus distance is smaller than the magnification, viewers use the binoculars to see the object because it cannot be seen with the naked eye.

Some Questions Arise in Your Minds

Which is the Best Magnification for Binoculars?

The 7x, 8x, and 10x magnifications are the best. Binoculars with these magnifying powers are commonly used for different purposes. Binoculars always show numbers like 7×28, 8×42, and 10×42.

The first one is magnifying power, and the second one is the diameter of an objective lens as we mentioned before also. It enlarges the original object depends on the type of binocular person used. These binoculars produce clear and stable magnification even when binocular lightly shake.

Which Binocular Magnification is Better?

Binoculars with 7x to 10x magnifying power show better magnification. Because these binocular are commonly used for many activities.

Binoculars with 7x magnification are better for the sports fan while seeing a match. 10x magnification binoculars are better for professional hunters.

They observe far distant places with the help of it. 3x to 5x range binoculars are better for the theatergoers. This range depends on the seat distance from the stage.

Which Binocular is Best For Hunting?

Binocular with a 10×50 model number is best for hunting. This SkyGenius binocular is most powerful. It is the best choice for the hunters or any other activities like racing, stargazing, and others.

1,000 yards is the field view of this binocular. It ten times magnifies the targeted object, or a hunter sees the object ten times closer to him.

What is Binocular Magnification?

It is defined as the ratio of objective focal length to the eyepiece focal length. Model numbers are written on the binoculars, which are essential for the viewers that tell the strength of that binocular.

Group of numbers specifies the binoculars. The numbers tell the information about magnifying power and diameter or size of that lens which closest to the targeted object (objective lens).

Conclusion: Binocular Magnification Chart

In binoculars, two telescopes are placed alongside. When people see through it, they can use both eyes to observe the object because they adjust in the same direction.

Binoculars are commonly defined by a group of numbers like 7×42, 8×28, and 10×42, etc. 7x, 8x, and 10x represent the magnifying power of the binoculars means the object is 7, 8, and 10 times closer to a viewer when seeing with the naked eye.

And 42mm, 28mm, and 42mm are the diameter of the objective lens. As diameter increases, it gathers maximum light to concentrate and form an outstanding resolution.

A sharp and clear image is produced when you can use binocular of the larger objective lens is used. The object lens has a smaller focal length and produces an inverted and erect object image in the device.

Hi! I am Elliana-Rose, Founder of The Hunting Binoculars. Our commitment is with the satisfaction of our users and their ease; we aim to provide manageable products and premiums. I hope you enjoyed it.

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