Which Is Better 7 X 70 or 10 X 30 in Monoculars? – Detailed Guide with FAQs and More

Do you want to know which is better 7 x 70 or 10 x 30 in monoculars?

Let’s find out.

Which Is Better 7×70 or 10×30 in Monoculars?

The 7×70 monoculars are much lighter than their larger counterparts 10×30. So if you’re carrying around two pairs of monoculars, you may want to consider buying the smaller ones. You’ll need some experimentation to find out which one fits your needs better.

What Do Binocular Numbers Mean?

Binocular Magnification

The first number in the “8×42”  is its magnification.

Binocular magnification refers to power. You will see an “X” next to the 8 in my examples, which means it belongs to the number. 8× means eight times magnification.

Why Is Binocular Magnification Important?

Binoculars help you see objects at a distance more clearly by making them appear bigger than they really are.

All binoculars with 8x magnification offer the same magnification. However, some binoculars may be better than others for certain uses. All lenses will magnify the image by 8x. Likewise, 10X42 will magnify ten times, and 12X50 will magnify twelve times.

How about 30-160×70?

This example comes from the Sunagor BCF30-160X70 MegaZOAM Binoculars. They have a maximum magnification of 30-160x and so they can adjust their magnification anywhere between 30 times and up to 160 times.

Objective Lens Size

The second number 8×42 indicates the diameter of the objective lens in millimeters.

An 8×42 binocular uses 42mm objective lenses.

Whereas 8×21 eyeglasses have 21mm objective lenses, they also have an 8x magnification.

Comparing 6X21, 8X21, 8X40, and 10X41. These have objective lenses of diameters 21 millimeters, 21 millimeters, 40 millimeters, and 41 millimeters.

Why is this Important?

The surface of the objective lens captures the image of the scene and sends it to the ocular (or eyepiece) lens which then transmits that image to your eyes.

Larger objective lenses capture more light and so the images seen are potentially brighter than on smaller ones.

If there is less light available for capture by the camera, then the more light that can reach the eyes the better.

A 42mm objective has four times the surface area of a 22mm objective, and so has the capability to capture four times more light than a 21mm objective.

Binocular lenses that magnify by twenty-five times capture over twelve times more image detail than ten times magnification.

42mm Binoculars

However, for now, just know a 42-millimeter binocu­lar, like an 8x 42 or 10x 42, is considered to be the standard full-size instrument and a good compromise betw­een size and light gathering abilities.

Mid Sized Binoculars

Mid-size instruments usually have lenses between 30 and 32 millimeters (1 inch). They’re perfect for use at any time of day but aren’t ideal for use in very low lighting conditions.


Compact binoculars with lenses between 20–28 millimeters (8–12 inches) long are usually called “compact” binoculars.

Which Is Better 7 X 70 or 10 X 30 in Monoculars? - Detailed Guide with FAQs and More

Which Is Better 7 X 70 or 10 X 30 in Monoculars?

Frequently Asked Questions FAQs

What is the best magnification for bird-watching binoculars?

If you’re looking to buy binocular lenses for birds, you might want to consider buying high-magnification ones.

For general bird-watching binoculars, the best magnifications are 8x (8-Power)

You might want to consider using different magnification ranges if you’re observing different types of birds.

What size binoculars are good for bird watching?

Magnifications aren’t the only thing that matters when choosing binoculars. Other factors include weight, ease of use, durability, and price.

The other important factor determining whether you’re going to be able to see the moon is the diameter of the objective lens (or “big end”) which determines its light gathering ability, the field of view, and cost.

Magnification and objective lenses come with their own set of tradeoffs.

Are 10×42 binoculars good for bird watching?

If you’re looking for good quality binoculars for general use, then the next step up from 10×50 binoculars would be 10×42 binocular lenses.

However, they also increase the magnification of the bird’s size by up to 25%. That is not insignificant.

If you have strong eyesight, you might want to consider a 10×42 pair of binoculars as your primary bird-watching binoculars.

For most people, 10x binoculars would be best suited for open country birding, but if you mainly want to look at birds up close, then these may be a better fit for you.

If you’re looking for something to help you spot birds from far away, then these are probably not right for you.

You might want to consider using a spotting scope for this kind of bird watching, which allows for up to 60 times zoom.

Are 10×50 binoculars good for birding?

10X50 binoculars aren’t really suitable for general birding because they’re too heavy and have some other disadvantages.

Can they work for birding? Yes.

We wouldn’t recommend 10×50 binocu­lars for birds.

Are 10×25 binoculars good for bird watching?

Yes, 10×25 binocu­lars are not good for birding. The 2.5 mm exit pupil is too dim. The fovea will be so small that the eye will shake even more noticeably.

Are 12x binoculars good for bird watching? 15x?

No, 12x and 15X binoculars are not suitable for birding.

For all the reasons 10x are difficult, any more than 10x magnification makes them impossible to use.

If you’re looking for more magnification than 10x, you’ll need to consider buying a spotting scope with a tripod. Spotting scop­es usually range from a magnification of up to 60x.


Monoculars are the best choice for a variety of different types of photography. They provide high-quality images and can be used in dimly lit conditions without any additional equipment.

Monoculars have existed for thousands of years. The earliest known monocular was invented in China by Zhang Heng (78–139 AD). He called his invention “xiangshan”.

If you have any comments or suggestions, please leave them below.


  • John Moses

    John is the Editor in Chief here at The Outdoor Stores. His area of expertise ensures that there is no one better to suggest which rifles are most suitable for your hunting experience. He is also available for you to contact him personally to discuss the types of animals you want to hunt and the terrain you will be hunting on. Feel free to read his posts for expert opinion on Rifles, Scopes, Rangefinders, Bonoculars and Monoculars.

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