Magnification and Lens Size in Scopes: What’s the Right Choice?

Wondering which lens size and magnification to choose for your new scope? You’ve come to the right place.

This guide provides clear and comprehensive advice to help you select the right lens size and magnification for your needs. With our expert tips, you’ll be able to make an informed decision and find the perfect scope for your optics goals.


Scopes are a great tool for observing the natural world from up close or afar. But, depending on the viewing application, choosing the right combination of magnification and lens size is key to ensuring a clear and quality viewing experience. This guide will provide an overview of how magnification and lens size affect your view and will provide tips on making the right choice.

Understanding how magnification affects your view involves knowing that it is the ratio between an object’s apparent size when viewed with a scope compared to its actual size. The higher the magnification, the more powerful the optics are – meaning objects appear bigger in the scope viewing area compared to their actual size out in nature. Meanwhile, lens sizes refer to how large a “window” you have when looking through your scope – this window is determined by two factors – objective lens (front lens) diameter and field of view (FOV). The larger objective lenses allow more light into your eyeviewing , making details clearer and crisper; meanwhile FOV refers to how much of your environment can be seen at once when looking through your scope.

So when you’re deciding which combination is right for you, it’s important to choose a magnification that allows you to easily identify subjects while providing detailed information; likewise, select a lens diameter and FOV that lets you observe scenery with relative ease. Keep reading for further details on this selection process!

Definition of magnification and lens size in scopes

When considering the purchase of a scope, one of the main factors to consider is how to determine the best magnification and lens size for your intended use. Magnification is expressed in numerical terms, such as 4x, 6x, 8x, 10x and so on. Lens size is also expressed numerically using millimeters (e.g., 40mm).

Magnification determines how large an object or target will appear when it’s viewed through a scope. For example, with a magnification of 4x (4 power), an object that appears 1 inch wide at 1000 yards away will appear four times larger than it does at that distance. With high-powered scopes — 20x or greater — objects can appear up to 20 times larger than normal at the same distance. However, higher magnifications make it more difficult to maintain a steady view of the target due to hand tremors and vibrations from walking or other movement.

The lens size determines how much light is allowed into your scope by controlling the diameter of the objective lens (the large lens on the front). Larger lenses gather more light and make for brighter image projection inside your scope; brighter images allow for greater detail in murky conditions like thick fog or heavy shade. Generally speaking, scopes intended for long range shooting are outfitted with lenses no smaller than 40mm; those intended for nearer objects can have 32mm lenses or smaller depending on available space in terms of scope length and weight constraints imposed by its mounting location (elevation/windage screws occupy valuable space).

Importance of selecting the right magnification and lens size

The power or strength of your scope will determine how much you can magnify a target. A higher magnification will help you see even tiny details in objects such as birds, plants, and insects that require more magnification. The lens diameter is related to the amount of light capture and image brightness. The larger the objective lens, the more light it collects and the brighter the image becomes. As a result, a large lens is best for observing at greater distances because of its ability to provide better contrast and a sharper focus.

Choosing an appropriate magnification and objective lens size for your scope will help you get optimum performance out of it no matter what type of activity you are using it for — whether it’s bird watching or hunting. Factors that play an important role in selecting a suitable magnification and lens size include viewing distance, target size, optical requirements (such as contrast), type of object being viewed, environment conditions, age group viewing through the scope (size/distance from it) etc.

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It’s important to note that increasing magnification also reduces overall field of view; as image power increases so does its ‘exit pupil’ size—a small circular opening that sends light into your eye—which affects how much space players can cover at once with their scope effectively. If exit pupil is too small then viewers may experience fatigue quicker or may even find it difficult to find relatively fast-moving objects in your scope field view due to its limited range of coverage area per look-through cycle . Therefore selecting the right combination depends upon individual needs and individual comfort level with certain prism systems that have different exit pupil sizes related to their respective magnifications . Thus make sure to test out different combinations yourself before investing in one .


Choosing the right magnification for a scope depends on the type of shooting you plan to do. High magnification scopes are great for target or Varmint shooting and long-range target shooting, while lower magnifications are better suited for hunting due to their wider field-of-view. Higher magnifications also make it more difficult to keep the scope on target and track moving objects, or factors like breeze or temperature can affect a scope’s ability to maintain its accuracy at higher magnification levels.

It’s important to remember that sometimes the highest power magnifications aren’t essential and may be detrimental depending on your needs. The most commonly used range of magnifications is from 3x – 9x and many scopes offer variable zoom feature so you can adjust quickly between different levels of magnification as you spot different targets. Generally speaking, 3x – 9x is sufficient for most applications; here are some common uses, along with which magnifications will work best for them:

  • Hunting: 3x – 12x
  • Prone & benchrest shooting: 8x – 10x
  • Target Shooting/Varminting: 23+x or higher

Fixed vs. variable magnification

Fixed magnification scopes have a set magnifying power, and cannot be adjusted. Generally, fixed magnification scopes have a higher effective light gathering power, therefore allowing for a brighter image than variable magnification scopes. Fixed magnification scopes are best suited for long range target shooting, as there is no way to adjust the level of detail or clarity.

Variable magnification scopes allow the shooter or observer to choose the degree of amount of detail they want in the image and adjust it according to their own level of comfortliness. Unlike fixed power optics, variable power optics can often reach complex zoom levels (for example 12-48x). These kinds of scopes are great for hunting and long range shooting where adjustable magnifications are necessary at times. Variable power optics often come with some sort of parallax adjustment as well which gives you more flexibility in focusing in different distances.

Pros and cons of different magnification ranges

Choosing the right magnification range for your scope can be a daunting task. While higher magnification ranges offer clearer and sharper images, they also have the potential to reduce field of view and may not be suitable for certain activities. On the other hand, lower magnification ranges provide wider fields of view but can come at the cost of image quality. Below is a summary of the pros and cons of select magnification ranges so that you can make an informed decision when shopping for a scope.

Low Magnification (1-4X): Low magnification scopes are popular for close-up shooting or fast-moving targets because they offer wide field of view. Low magnifications also provide instant target acquisition when hunting game such as deer, turkey and hogs. These scopes are ideal for shooting upland birds in thick cover, or even big game in open country where tracking moving animals requires quick target acquisition and superior peripheral vision. The downside is that you may sacrifice some image clarity due to the low magnification levels in comparison to higher powered scopes.

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Medium Magnification (4-9X): This popular range offers significant detail at normal hunting distances while still giving you a decent field of view compared to higher magnifications. Medium power scopes work best in open terrain where you’re likely taking shots further away than with low power but not quite as far as with high power optics(10X and up).

High Magnification (10+X): High powered riflescopes are favored primarily for their ability to discern details even at long distances. Specialized long range hunting calls for extreme accuracy, which is why most serious hunters opt for these optics if their targets tend to flee before they can take aim at close or middle range capacity.

Choosing the right magnification for your needs

Having the right magnification for your needs is an important part of making sure that you get the most out of your scope. The right choice will depend upon what you are observing and where you plan to observe it. Whether you are looking at a distant star or keeping up with game on the plains, having the right lens size can make a big difference in the quality of picture you get.

When selecting your lens size and magnification, there are three factors to consider: field of view, light-gathering capabilities and pricing. The field of view (FOV) will dictate how much of your target area can be seen at once. This can be important for hunting applications where you may need to keep an eye on a larger area than with astronomical viewing. The light gathering capabilities will indicate how brightly objects may appear when observed through your scope; a larger objective lens allows more light into the eyepiece which makes far away objects easier to see. Finally, pricing will vary based upon overall quality and strength as well as product availability.

Generally speaking, lower magnifications such as 6x-8x provide good FOVs while still providing good light gathering abilities without too much distortion or aberrations in images. As magnification increases beyond 8x, light transmission begins to decrease quickly unless accompanied by a corresponding increase in objective diameter which adds cost quickly due to optics quality considerations. As such, it’s best to select magnifications that offer excellent FOVs while still providing acceptable optical performance for your needs often with 10x-15x binoculars being considered ideal for many various hunting scenarios and larger objectives for birdwatching or star gazing applications allowing higher magnifications such as 15x-30x before experiencing significant distortion effects on images due to aberrations associated with vibration or battery issues common with higher magnification scopes with small objectives lenses attached.

III. Lens Size

The lens size of a scope is measured by its diameter in millimeters and is typically one of the primary considerations when making a decision on your purchase. Larger lenses allow more light to enter the scope resulting in brighter, clearer images with improved color fidelity. In addition, larger lenses can reduce the amount of chromatic aberration or color fringing around the edges of an image that you may experience with some lower-end scopes. Smaller lenses are sometimes less expensive than their larger counterparts, but they may be unsuitable for certain applications due to restricted light gathering properties and limited field view.

In general, when selecting a scope it’s best to purchase one with a lens size that matches the requirements for your intended activity. Larger objective lenses generally provide better low light performance, better resolution and wide fields of view; however, it is important to remember that size isn’t everything as both good and bad optics can exist in any lens size. A quality 50mm scope will outperform some higher-end scopes with smaller front ends in every situation except low light viewing. Therefore, prior to making any decisions you should consider both your budget limitations and what type of viewing activity you plan on using your scope for most often.

Objective lens size and its impact on brightness and clarity

When selecting a scope, in addition to its magnification capabilities, it is important to understand how the size of the objective lens affects the image you see. The objective lens is located at the opposite end of the scope from where you look through when sighting in your target. It is also referred to as the front lens or aperture of your scope because it is large enough for light to pass through.

In terms of size, a larger lens can make for brighter images with improved clarity and sharpness, however it may also add additional weight and bulk to a scope. Smaller lenses, on the other hand, are more lightweight and portable but may offer poorer image quality.

The most important factor in determining the ideal scope for you will come down to personal preference and budget constraints. Generally speaking, higher-end rifle scopes have larger optics than budget scopes that sacrifice some optical clarity for weight savings. If using your rifle for hunting or accurately spotting targets over long distances, then going with slightly larger lenses may be beneficial though they also require greater financial investment into higher-end optics capabilities.

In general, it is recommended that hunters looking for a good balance between size and performance select objectives grouped within their preferred size range — usually between 40mm – 56mm — based on their individual requirements to optimize brightness and clarity within their budget constraints. Additionally, many scopes feature adjustable magnification levels so users can increase or decrease magnification levels per individual needs without necessarily needing to change out lenses depending on range conditions or hunting environments.

Pros and cons of different objective lens sizes

When selecting a scope, an important factor to consider is the size of the objective lens. The objective lens relates to the total amount of light that reaches your eye and ultimately determines how much light can be seen through the scope. Generally speaking, larger objectives provide brighter images while smaller objectives get lower-light performance but with a trade-off in field of view. It’s important to understand the pros and cons associated with different objective lens sizes in order to make an informed decision about which scope best suits your needs.

Smaller Objectives: Smaller lenses usually range from 24mm-40mm. This size typically offers superior low-light performance but with a reduced field of view and magnification power compared to mid and large range optics. Typically these scopes will provide zero after 7-9X since most come without adjustable eyepieces or zoom capabilities due to their small scale design being used for CQB situations or other short distances where magnification doesn’t offer a considerable advantage.

Medium Objectives: Medium objective lenses usually range from 42mm–56mm and offer good performance in both low-light conditions as well as increased field of view over their smaller counterparts while still providing outstanding accuracy at higher magnifications typically up to 16X power. These scopes are well suited for intermediate distances making them popular among sporting shooters, tactical competitors, and some hunters alike especially those shooting at slightly longer ranges where higher magnification may not be necessary but is still preferred over lopping off either side of your picture with a small scope’s reduced FOV.

Large Objectives: Large objectives lenses range from 60–100mm making them one of the largest commonly found on riflescopes today though ultra large sized ones can exceed this diameter depending on intended use case such as long distance hunting rifles needing every bit of possible light captured through admission in order to achieve maximum accuracy when shooting across great distances (typically >500meters away). Just like their medium sized counterparts they too provide good low-light performance while offering large zoom capabilities allowing you to see even further out than their smaller brothers can afford (upwards around 25x) allowing you a bonanza of options when deciding just how far away you’d like your picture clarity extended out too!

Choosing the right lens size for your needs

When shopping for a scope, lens size is one of the most important factors for consideration. The size of the lens used has a direct impact on both the magnification range and field of view that a given model offers. With such an important choice to make, it is essential to understand how different lens sizes affect performance.

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The most common range of lens sizes falls between 20-60mm in diameter. As a general rule, lenses under 40mm are considered more “compact”, while larger sizes are considered “full-size”. It follows that smaller lenses have less magnification power and field of view while larger lenses offer more. It’s also important to note that compact models will generally weigh less than their full-size counterparts.

When choosing the right lens size for your needs there are several factors to consider: budget, space restrictions, target type and environment. Depending on your needs you may need something small and lightweight or something larger with greater performance characteristics such as better image quality or lower light gathering capability.

If you’re operating within tight budget constraints – or if you plan on using your scope in low light settings – you’ll want to opt for a full-size model with better optical capabilities. On the other hand, if you plan on using your scope at shorter distances and don’t mind compromising image quality then compact models can offer an affordable solution in a form factor that may be more desirable than their full-size alternatives.


When selecting the ideal scope and magnification setting, it’s important to understand the features that affect their performance. Most rifle scopes are equipped with adjustable optics so that the shooter can choose their optimal level of magnification for the shooting situation. Increasing magnification provides a clearer image, but decreases field of view, so you will have to decide whether to compromise between the two.

In addition to understanding magnification and field of view, you must also consider eye relief and lens size when selecting a scope or adjusting its zoom settings. Eye relief is an important factor when shooting larger caliber rifles, as too much recoil can cause serious injury if your eye is too close to the eyepiece. Lens size contributes significantly to light gathering capability and resolution—larger lenses gather more light, creating a brighter image with improved detail and clarity.

By knowing your needs and understanding how your scope works, you can make an informed decision regarding the right magnification and lens size that meets your needs while remaining within budget constraints. With careful selection and consideration of these factors, you’ll be best prepared for whatever lies ahead.

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