Best Rifle Scopes, Buying Guides & Tips, Riflescope Tips

How To Choose The Best Optical Rifle Scope For Your Needs

optical scope

How To Choose The Best Optical Rifle Scope For Your Needs

There are scope terms, numbers, and all the other various lingo that goes along with searching for a good scope. With all these new things to consider, the inexperienced scope user can be left feeling a little overwhelmed.

You don’t need to be an optical physicist to have an above-average understanding of how hunting optics and scopes work and how to use that knowledge to make a good purchase. That said, scopes are incredibly complex devices that rely on a myriad of moving parts and principles to function properly. An understanding of how these systems work, and what that means for performance in the field, is critical to choosing a scope you’ll be satisfied with.

All you need is to learn the basics and you’ll be off and hunting (or target shooting….) with a new, high-quality scope. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

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Things To Consider When Buying an Optical Scope

Here are some things you should know about optics before you hit the gun store.

If you have been researching scopes you have come across some terminology that is probably new to you. Optics have very specific terms and you need to learn a few to get started.

Not only will this help you know what kind of scope you need, but it will also help you understand reviews and articles regarding the scope you may want to choose. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

1. Tube Diameter Affects Weight

In recent years, scopes with 30 or 34mm tube bodies have gained popularity. Though larger and heavier, the higher diameter tubes allow for larger internal components, which do a better job managing light. The larger tubes are also typically more robust than the 1-inch models. As with any choice when selecting optics, there will be trade-offs when selecting tube diameter.

Scope Buying Tip: If your hunt involves long hikes or you need to keep optics as compact as possible, check out the 1-inch models. They may give up some light management, but they will save ounces on your rifle. Meanwhile, if your hunting or shooting activities are mainly stationary, or weight isn’t a serious consideration, 30mm may be something to consider. You might benefit from the stouter construction this chassis can offer.

2. Objective Lens

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This is the lens on the front of the scope. It is measured in millimeters. The larger the objective lens, the more light it lets in.

This is good for low light conditions like dawn or dusk. The drawback of a larger objective lens is that it gets bulky and may need to be mounted higher on the rifle.

The size of the objective lens is after the magnification of the scope. In a scope that is 6-12×40, the objective lens is 40mm. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

3. Adjustable Objective

Some scopes feature an adjustable objective lens. It is a ring around the lens that turns to allow for adjustments, just like a camera.

This feature is best for long-range shooting. Maybe some midrange. It allows you to adjust the reticle for your own eye.

Scopes that don’t have an adjustable lens aren’t worse. The manufacturer sets their scopes to be parallax free at a certain distance. You won’t be able to adjust it.

4. Understanding “Exit Pupil”

The low-light performance of a scope relies on many factors. No other factor plays as significant a role as exit pupil. Simply calculated, the exit pupil is found by dividing the objective lens diameter by the magnification. For an 8×32 binocular chassis, the exit pupil is 4mm. On a 2.5-10×50 riflescope, it ranges from 20mm on 2.5X to 5mm on 10X.

A general rule of thumb: keep the exit pupil above 4mm when being used in low-light conditions. This provides your eye an adequate, appropriate amount of light when it’s dilated in darker field conditions. During brighter conditions, your eye’s pupil constricts. That means you’ll need a smaller exit pupil, and it’s, fortunately, suitable at these times.

Scope Buying Tip: A hunting scope should provide a 4mm exit pupil throughout the magnification range. This may mean less magnification, or possibly getting a larger scope than planned. You’ll want to understand the trade-offs in performance. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

5. Avoid Over-Adjustment

In my experience, over-adjustment causes more perceived issues with riflescopes than any other issue. While having a scope with a lot of internal adjustment may seem like a good thing, in reality, it is simply a crutch for poor mounting technique. The goal when mounting a scope should be zero adjustments to the turrets to sight the optic in.

Scope Buying Tip: Bore-sighting is a common service. When using a bore sighter, people tend to crank the turrets into place without keeping track of the adjustments. The best-case scenario is the scope isn’t as clear as it should be. Worst case, it can’t function because the erector assembly is floating or pinched. Opt for the live-fire sight-in if you can make it happen.

6. Adjust Your Diopter

Riflescopes are equipped with diopter adjustment to help focus. In a riflescope, the diopter, at the back of the eyeball, is used only to focus the reticle. It should not be adjusted to focus on the target. Diopter adjustments are meant to be set for your eye, then left alone. To set your riflescope diopter, look through the riflescope at a plain background closer than 20 feet. Adjust the diopter until the reticle is clear. Once the diopter is set, do not adjust it. There is no need.

Failure to adjust the diopter on your riflescope can lead to a fuzzy reticle, which isn’t going to provide the most accurate aiming possible. It’s common for people to complain that, when using binoculars for extended periods of time (or sometimes if using them at all), they suffer from headaches. The most likely cause is not having the diopter properly adjusted. Much like using glasses that aren’t prescribed for your eye, a binocular that hasn’t been adjusted properly is going to lead to a headache.

Scope Buying Tip: Feel free to ask the store to help put your scope in focus. Unless the scope has an AO or side-focus feature, the diopter is not for adjusting target clarity. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

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7. Reticle Choice Confusion

A reticle is a crosshair or aiming point of your scope. Recently, ballistic reticles have garnered a lot of attention. Hunters and shooters alike are drawn to the ease of use and accuracy of ballistic reticles that match the round used in the field. Sadly, this has also led to a great deal of confusion regarding these reticles and their capabilities.

No other reticle suffers from the amount of misinformation as does the Mil-Dot reticle. Often referred to as a ballistic reticle, it’s function isn’t truly ballistic. A ballistic reticle is designed around the ballistic curve of a given round. As any round travels downrange, the number of drops increases as it loses velocity. That is to say that the drop of a .270 bullet from 200 to 300 yards is less than the drop of the same bullet from 500 to 600 yards. In a ballistic reticle, the Aimpoint that corresponds to those yardages must be further apart to be truly ballistic.

A Mil-Dot reticle is comprised of dots, or half dots, that are evenly spaced throughout the reticle field. To keep things simple, we will assume Mil spacing is 3.6 inches from the center of a dot to the center of another dot at 100 yards when used on 10X. Because the dot distance is evenly and consistently spaced, it cannot account for the ballistic curve of a bullet at long range. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

The Mil-Dot is actually better suited as a range-finding reticle. Because the dot distance is known and can be recalculated depending on magnification — if a target of known size is being shot — you can use a mathematical equation to solve for the distance. Those trained on the Mil system find it quite useful, but for most shooters, it requires too much calculation to be done on the fly for it to be used effectively.

Scope Buying Tip: If a ballistic reticle is what you need, steer away from the Mil-Dot. Understand exactly what you want the scope to do then work with your gun store to understand the implication of a choice in the reticle.

8. Parallax Error is Not a Focus Issue

Parallax is the most complicated optics issue on this list. Scopes equipped with an adjustable objective (AO) or side-focus system can correct for parallax error. Though it can be corrected with a side-focus system, parallax error is not a focus issue. Parallax error can cause the point of impact variance because the reticle and the target are not on the same optical plane.

The reticle lens inside the scope is viewed over the top of the target image, for this instance, 200 yards away. On a fixed parallax scope, the parallax is corrected for at 100 yards. This means that the optical system at 100 yards has compensated for the distance. So when you move your head slightly, the reticle and the target move together, as if they were on the same optical plane. At 200 yards, that same slight movement of your head would show that the reticle can float off target.

For most hunting situations, the issue is negligible. The movement is typically measured in inches — or fractions of an inch — but for precision shooters that could mean missing the target completely. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

AO and side-focus systems adjust internal lenses to remove that error. While making this adjustment, the focus of the target often improves as well. It is important to note, however, that being in focus doesn’t mean parallax has been resolved. Also, resolving parallax doesn’t mean the target will be in perfect focus. The only way to know that parallax is corrected is by moving your head slightly, up and down and side to side, to make sure that the reticle and target image or moving together in unison.

One common mistake: the assumption that if you turn the focus knob to 100 yards, sight-in the rifle and then turn it to 200 yards, that the rifle is now set to that yardage. That’s not the case. AO and side-focus systems do not adjust the reticle.

Scope Buying Tip: If parallax correction isn’t necessary, steer away from those models. More often than not, especially with hunting optics, keeping it simple is the best way to go. Features that complicate functionality just open the door for errors to be made in the field.

9. First Focal Plane Options

First focal plane (FFP) scopes are becoming more common as the technology it takes to produce them becomes more cost-efficient and the price of the scopes dips.

An FFP scope arranges the reticle and the target lenses of the optical system such that they are affected equally by a change in magnification. More traditional second focal plane scopes are designed in a way that the target is magnified, but the reticle remains a constant size.

Deciding if an FFP scope is right for you depends on several factors, but primarily it is a function of reticle choice. Knowing what we know about Mil-Dot reticles, it is easy to see that if the reticle changes in conjunction with the magnification it makes the reticle easier to use. The dot-to-dot distance will always be 3.6 inches, eliminating one calculation that would need to be made in the field. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

Similarly, for a true ballistic reticle, the demand that the scope remains on the designated power the reticle is designed around is now gone, making the scope more flexible. Where problems arise with ballistic reticles is in the less-specific ballistic reticle offerings. For those scope designs that offer a ballistic reticle that isn’t specific to a caliber, the changing magnification allows the reticle to be tuned, in a way, to that specific round. With an FFP scope, that flexibility is taken away, because the reticle is always going to be related to the target in the same spaces each time.

Scope Buying Tip: Budget drives most decisions. FFP scopes are still considerably more expensive than traditional second focal plane models, so for shooters wanting to take advantage of the measuring abilities of the Mil-Dot reticle, an FFP scope may be an option. This is also for those looking for a scope dedicated to a specific caliber. For customers who need more flexibility or a scope that may be moved from one rifle to another, the more traditional second focal plane (SFP) scopes may be the solution.

10. Second Focal Plane

With a second focal plane scope, the reticle doesn’t grow and shrink with the change of magnification.

When you change your magnification to the higher range of your scope, you lose the field of view with the first and second focal range. With the second focal range, you will not lose part of the reticle as you do with the first focal range.

the second plane helps hunters find their target much easier second focal plane scopes are the standard. They are more common, especially with American made scopes. They are usually more affordable than first focal plane scopes and are accurate at all magnification levels. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

11. Mil Dot Reticle

A mil dot reticle is basically the metric equivalent of the MOA scope. A mil dot reticle will have normal crosshairs with a series of dots, spaced along the horizontal and vertical crosshairs.

The center of one dot to the center of the next dot is exactly one milliradian or mil. There isn’t a dot in the middle of the crosshairs so your view is not obstructed. You count the crosshair intersection as a dot.

Mil dot reticles are the scope of choice for really precise shooting. If you find metrics easier than the American measurements of feet/yards/miles, then a mil dot reticle is a good choice.

12. Mil VS. MOA

Either MOA of Mil Dot will work well. There really isn’t one that is better than the other. The biggest factor is you. Whichever one you are the most familiar with or the most comfortable with, should be the one you use.

You don’t have to stress over which one to go with. Either one will work just as good as the other.

There are a few differences between the two.

  • ¼ MOA adjustments are slightly more precise than 1/10 mil
  • Mil values are slightly easier to communicate
  • If you think in cm/meters the math is easier with mil
  • If you think in inches/yards the math is easier with MOA
  • If you have a shooting buddy who uses one, you may want to be on the same page as they are
  • 90% of the pros use Mil
  • There are more options with Mil

Many entry-level scopes have a Mil Dot reticle but the turrets are ¼ MOA adjustments. This can limit how quick you are with second-round adjustments. It’s always best to make sure you get a scope that has matching reticle and turret systems.

There is quite a bit of science and geometry behind this, that goes beyond the scope of this article. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

You can check out this video for a clear, easy explanation and check out the books he recommends at the end if you are still curious.

13. Magnification

Magnification, or sometimes called power, is the amount of magnification the scope has. If your scope has 9x magnification, your scope allows you to see nine times farther than the naked eye.

Scopes will have either a fixed or variable magnification. Fixed means just what it says, the magnification is fixed. A variable will let you adjust the magnification power.

A scope with a 3-9x magnification power allows you to see three times, and up to nine times further than the naked eye. A variable scope with a 3-9x magnification is a great beginner’s scope.

Recommended Optical Rifle Scopes

1. Athlon Optics Ares ETR

Regardless of price point, a serious precision optic should feature a first-focal-plane (FFP) reticle and multicoated, extra-dispersion (ED) lenses, and Athlon’s 4.5-30x56mm Ares ETR does just that. It boasts 110 minutes (32 miles) of total elevation travel, with a precision erector system and stainless steel turret design. The turrets are impressive because they offer solid clicks and lockdown to prevent accidental changes. The healthy magnification range will let you make good use of Athlon’s APRS1 reticle.

2. Bushnell Elite Tactical DMR II Pro

The Elite Tactical line of optics from Bushnell seems to know no bounds, and the new 3.5-21x50mm DMR II Pro builds on that legacy at just over 13 inches long with some of the best turrets to boot. The new G3 reticle features 0.5-mil markings, with finer markings near the outer edges. You can also opt for an illuminated version as well as the Horus H59. The glass and coatings are top quality, with all the abbreviations and designations that others have, but the DMR II Pro comes with an excellent Throwhammer lever installed for quick magnification changes.

3. T-Eagle ER 6-24X50SFFLE Hunting Tactical Rifle Scope

Excellent scope for long-range deer hunting, this one from T-Eagle has everything you want in scope and a lot more. It’s advanced yet simple at the same time, making this an ideal scope for beginners and veterans to the game alike.

First things first, this is a First Focal Plane reticle, which is ideal for shooting long range. The reticle seems to shrink or grow in size as you zoom in or out of your prey. That makes for a very clear picture of the huge 44mm objective lens.

The glass-etched reticle is an illuminated Mil-dot reticle, which is excellent for long-range accuracy. Most FFP and mil-dot reticle scopes in the market today are at least twice the price.

Multicoated lenses provide a very clear and high-contrast picture, as is required when shooting deer long range. The picture quality is excellent and stays consistent throughout the entire zoom range.

The scope’s tube is made out of aircraft-grade aluminum, which has exceptional mechanical and structural integrity and will hold up to all manners of battering. The argon purged lenses give top class waterproofing and thermal stability.

4. EOTech Vudu

The EOTech 5-25x50mm Vudu scope offers sharp, clear glass while being extremely compact. It’s 11.2 inches long and packs 25X magnification, which is easy to tap into using the included throw lever and smooth-actuating magnification ring. In terms of reticles, you can choose between the Horus H59 or EOTech’s own mil-style MD3 reticle, both of which are mounted in the first focal plane. The elevation turret has a push/pull locking system that is extremely short in movement. And the scope tracked well in testing, as it easily helped me shoot out to a mile.

5. Kahles K525i

One of the oldest optics manufacturers in the world, Kahles has come on strong more recently. With the 5-25x56mm K525i scope, you’ll find excellent glass—as you might expect from a company under the Swarovski umbrella—but there’s more. For instance, the windage knob can be had on either the left or right side of the optic, and it comes with Kahles’ Twist Guard, a free-spinning wheel on the outside of the windage turret that prevents accidental adjustments. That way you don’t have to lock and then unlock turrets. Finally, five different reticles are available for this scope.


I hope you learned some things with this crash course on scopes. I also hope you have figured out what kind of scope you need, the features you need, a good budget, and even saw some great choices as you shopped through some links. Hope this post could help you find the best optical scope, if any questions, feel free to contact us.

T-Eagle always offers high-quality rifle scopes at a friendly price, our mission is to provide you with an excellent shopping experience. If you have a large order and also other concerns, please do not hesitate to contact us, we will reply to you in 24 hours. Many thanks for shopping with us!

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