Scopes and Sights 101: A Complete Guide
Since the invention of telescopic sights for weapons in the late 1830s. These marvelous pieces of science and engineering have proved to be a revolutionary improvement in ranged warfare. Starting as fragile and long tubes, these firearm optics have evolved into tools complex as an owl’s eye. Being capable of identifying targets even in the dark.
There’s a ton of information on scopes and sights on this vast internet ocean. But you’re about to read a detailed guide that is comprehensive and simple like no other. By the time you are done with it, you’ll not only have a clear knowledge of these optics. But you’ll also be aware of how to choose the best of each.
Feel free to browse the article or use the table of contents to skip right to your most pressing questions.
Scope and Sight Basics
Moving to the first step, let’s understand the basics first. That includes terminologies, principles, and other nitty-gritty of firearm optics.
What is a Scope?
A scope or we should better call it a telescopic sight or a firearm scope. It is a long or short metal tube that has glass innards. It works like a telescope and allows the user to view distant objects nearer and clearer.
It’s like viewing an object through a magnifying glass. A scope allows the shooter to view the target clearly and aim at it with accuracy and often, precision. There are low-power scopes and high-power scopes that allow the user to cover short or long distances for sighting targets.
What is a Sight?
A sight can be seen as a version of the scope with one lacking factor - the magnification. Sight is a versatile term when speaking of firearms. The word sight may refer to the simple iron blades/prongs on the top of your weapon, known as iron sights. But since we’re discussing optics..
The term sight here will refer to non-magnifying optics that feature illuminated aiming point/s. These are powered by an LED light and are great for short range uses like close-quarter combat.
How Does a Scope Work?
The most important intrinsic property of scope is magnification. For which it has to rely upon lenses. A scope works on the principle of magnification. Which refers to the degree to which an object being viewed is enlarged.
The magnifying power of scope is denoted with an ‘X’. So if a scope can magnify an object five times, it will be called a 5X scope. A scope can have fixed or variable magnifying power.
Next, there’s the reticle a.k.a crosshair. It can be as simple as a ‘plus’ made by two intersecting wires, or a more complex design that is etched on glass and illuminated by LED.
A scopes ‘turrets’ are small knobs on the side and top of the scope. These allow you to adjust the position of the reticle to counter factors like wind and gravity that affect a bullet's path.
Lastly, there’s a process called ‘zeroing’ that has to be done when mounting a scope on a rifle. To ensure that your barrel and scope are properly aligned.
How Does a Sight Work?
A sight works on the principle of reflection. It uses a LED that projects a beam of light that passes through a collimator. Which then focuses it into a red dot and further projects it onto the main lens. This red dot is then used as the reticle. The color and size of the dot vary from model to model. These sights can either have an openly exposed lens, or a closed housing that looks like a shortened scope.
Reflector sights are offered in a variety of options. These are perfect for close-range engagements since they offer quick target acquisition and tackle the problem of parallax (more on parallax later in this guide).
Reflex sights do not offer magnification intrinsically. However, some specially designed sights can be coupled with a magnifier to extend the range.
The size of the dot defines the range for which the sight is suitable and accurate for. The size of these dots is measured in MOA (Minute of Angle). Cutting all the complex jargon, a larger dot is better for a shorter range since it covers a lesser area on the target. Whereas a finer dot is suitable for a longer range for the same reason.
Types of Scopes
The different types of firearm scopes can been segregated upon the most basic differences in features. Let's investigate these further:
Fixed or Variable Magnification Scopes
The most basic difference among scopes is the level of magnification. Some scopes offer a fixed magnification that can’t be adjusted. Hence limiting their use within a specific range. These scopes were more prevalent during earlier times when scope technology was in its cradle.
The other kind of scopes offer variable magnification, allowing you to adjust the magnification to get a clear image at different distances. These scopes are very versatile and can be used for a variety of purposes.
Long or Short Range Scopes
Scopes with low magnifying power (fixed or variable) are suitable for short range. For example, 3-9x or 1-6x or 1-8x scopes. These are mostly used with rimfire rifles. Whereas scopes with high magnifying power are used for long range. For example, 4-16x, 5-25x or even 10-50x. These are mostly used with centerfire rifles.
Then, there are spotting scopes that are used to spot targets and have very high power, but are not meant for mounting on a firearm.
Hunting or Tactical Scopes
This factor is directly related to the kind of reticle scope has. Hunting scopes generally have basic reticles with no clutter and advanced tech reticles. Whereas tactical scopes have more advanced reticles for estimation, advanced turrets, and several other distinctive features.
Scout scopes are known for their long eye relief (the distance between the rear end of the scope and the user’s eye) and low magnifying power. Mostly used for scouting and hunting.
As the name suggests, these are more compact scopes designed to be mounted on high caliber handguns.
Night Vision or Thermal Scopes
These are the most advanced scopes available today. They allow you to hunt/kill in the night. With a few variants offering features like video recording and range-finders.
To find out more information about night vision and thermal scopes check out this article!
Types of Sights
Sights aren’t as versatile as scopes. But then there are a few variants that you must be aware of.
Also known as Reflector sights, these work on the principle of reflection of an aiming point on a lens. These sights can be used with both eyes open and are known for their quick acquisition.
One important point to note here is that reflex sights are often confused with red dot sights. Basically, any sight that uses a red dot as an aiming point is a red dot sight.
Reflex sights were invented in 1918 and saw some service in WWI. These sights went on to be refined with the advancing tech and time.
Holographic sights, a.k.a holo sights are an advanced version of reflex sights. These use a complex system of laser diodes and mirrors to create a 3D like the image of the target.
Holo sights are the most advanced type of sights in use today. The U.S Military widely uses the EOTech 553 holographic sight. In fact, holographic sights were invented by EOTech in the late ’90s and it was the only manufacturer of holo sights until recently when Vortex shared the tech.
These sights use a laser light that projects a laser beam to marks the point of impact of the bullet. While they aren't an optic to 'look through', they still assist the same purpose as an optic.
Laser sights are typically available in red or green colors and are great for use in the dark. Or in situations where quick acquisition is imperative and aiming through the sights becomes difficult due to panic.
These sights are great for beginners, home defense, and tactical applications.
While these sights have little to do with optics. They still need an honorable mention. Iron sights are the most basic kind of sights you already get on a weapon when you buy it. But these sights can be upgraded to night sights or HD sights for better visibility.
Iron sights can be equipped with fiber optics or tritium/phosphor to create an illuminated sight for better visibility.
A great combination of optics and fiber optic sight technology is the Trijicon ACOG 4x32. An optic that is widely used by the U.S Military.
How to Buy the Right Scope or Sight For You
Coming to a very important discussion, let’s understand what factors should be kept into consideration when buying a scope or sight.
What is the Intended Purpose For the Optic?
The best method to evaluate what scope to buy is to understand your intended purpose. Here's a few considerations you should make about your use-case:
Range and Size of the Target
The most important factor when choosing an optic is to decide the range you’ll be using it for, and probably the size of the targets.
I understand that ‘size of the target’ can be a variable factor, but it can still be estimated. For example, whether you are planning to use your weapon to hunt squirrels at short range or big game at medium to long range. Or perhaps you’re a competitive shooter who has to shoot a human torso-sized silhouette at 1,000 yards.
The range and size will determine if you need a scope or a sight. Additionally, the size of the target will determine the size of the red dot when working with sights.
Typical Ambient Lighting Conditions
A scope gathers light from its surroundings, which in turn decides the brightness of the images. For scope with a large entry lens (a.k.a objective lens), images will be more crisp and clear in low light conditions.
As far as sight is concerned, the ambient lighting only concerns the brightness of the dot. Almost every optical sight comes with a brightness adjustment feature, so that’s not a problem here. Plus, night sights are designed for use at night.
Are You Hunting?
While there’s no written rule that you can’t use a complex optic for hunting...usually a simple scope is what’s needed most of the time.
Hunting is often done in short to medium range. So high-power scopes aren’t generally used for hunting.
As far as sights are concerned, their use should be kept within a range of 100 yards. Sights also work great on shotguns when hunting ducks or gobblers.
Competitions can be a versatile term when discussing optics. There are 3-gun competitions that range from one to 600 yards, F-class competitions that extend to 1,200 yards, and everything in between.
Long range competitions require the use of more complex reticles and scopes that can be calibrated extensively. Sights are mostly used for short range competitions on rifles, handguns, and shotguns.
If the competitor so chooses, a magnifier can be combined with a sight to extend the effective range.
Tactical Applications (Self-defense/Combat/Home Defense)
Now, this is where your life is on the brink. Any type of defense situation (whether offensive or defensive) requires a scope/sight that is durable, easy to maneuver, offer quick acquisition and are easy to adjust.
Unless you are a sniper, the scopes you’ll be using for tactical uses are low magnification with tactical reticles like BDC (bullet drop compensator). Many operatives prefer sights for close quarter battles where the engagement range is under 50 yards. Shotguns get a lot of advantages with open reflex/holo sights in such situations.
How to Choose a Scope
Once you’re identified your intended use, it's time to siphon out the best scopes from the vast sea of options. Let’s look at what you should consider:
Resilience to Your Use-Case
You'll want to find reviews that confirm the scope you're considering is durable enough to withstand the punishment and still maintain its zero.
On a general note, rimfire calibers are generally lesser recoiling compared to centerfire calibers. Furthermore, the level of durability will also depend upon the caliber of your rifle. A 22LR rifle is not going to put the scope through it's paces like a .338 Lapua will.
Heavy calibers have unforgiving recoil so a scope with ample resistance to shock and long eye relief is a must. Additionally, make sure the power of your scope matches the effective range of your rifle.
Make A List of Features You Want
Scopes come as limited in features as simple as a duplex reticle and fixed magnification, to including: night vision, video recording, ballistics computer, smartphone compatibility, and others. Determine what is a "must" vs. a "want" or nice-to-have.
Naturally, the more features, the higher the cost. There’s no hard and fast rule to sketch out the exact features that suit every buyer. It depends upon personal preference and also your budget.
However, durability, multi-coated lenses, and crisp turrets are some generally sought-after factors.
How to Choose a Sight
Let’s now focus (ba-dum-tsss) in on some considerations that should be kept in mind when choosing a sight:
Sights are more versatile compared to scopes. Mounting and dismounting them on weapons is easy if you have the right kind of setup.
Additionally, sights are often very compact. Which makes them suitable for rifles, shotguns, and handguns. There are also more compact sights that have been specifically designed for handguns and pistol-length submachine guns.
An important, and often the ultimate deciding factor for many buyers. Optic sights can offer a battery life ranging from a few hundred hours to five years.
Reflex sights are the most battery efficient. For example, the Trijicon Accupoint offers a battery life of five years on setting three. Whereas more complex optics like holographic sights have a significantly lower battery life of just a few hundred hours, as a result of their complex electronics.
Optic sights with long battery life and an auto-shutoff function are things to look for.
Brightness, Colors, and Complimentary Attachments
Almost every optical sight offers brightness settings. Some less and some more. Additionally, having the option to switch from red to green is preferable if you intend to be using it in daytime and nighttime settings.
Some sights also offer compatibility with night vision optics, magnifiers, thermal systems, etc.
Popular Optics Brands
Let’s discuss some of the best scopes and sight manufacturers. These companies are very renowned and have some unique propositions that make them stand out from the competition.
Top Rifle Scope Brands
Vortex: One of the most renowned optic manufacturers in the U.S and global market. With the largest range of optics. Vortex also offers a VIP warranty that covers its products against cosmetic damage.
Leupold & Stevens: One of the oldest and most trusted names in the global hunting optics market. The company invented the famous ‘duplex reticle’ and offers some very affordable scopes.
Burris: Affordable, very clear, and durable scopes with a wide range to choose from.
Primary Arms: The most affordable FFP (first focal plane) long range scopes.
Bushnell: Great affordable scopes mostly preferred by hunters due to their amazing low light clarity (the dusk & dawn series). They also offer a good range for beginners, rimfire rifles, and air rifles.
Nightforce: Fully American made scopes. High quality and reasonably priced inventory of long and ultra-long range scopes.
Swarovski: Austrian manufacturer renowned for its high quality long range scopes.
Check out all our brand reviews here!
Top Sight Brands
Aimpoint: This Swedish company is the world’s most renowned red dot sight manufacturer and its sights are widely used by militaries and LEO’s globally.
Trijicon: A name very familiar and respected in the U.S civilian and military sphere. Known for their extremely tough optics.
EoTech: The inventor of holographic sights and also the sole seller until 2019. Tad expensive but high quality sights. Used by U.S defense forces.
Vortex: Extremely popular among hunters and tactical operatives. Features some best selling models like from the Viper and Razor series.
Burris: Manufacturer of the best selling FastFire™ series of red dot sights for rifles, handguns, and shotguns.
See our entire lineup of sight manufacturer reviews below!
Other Sight & Scope Considerations
There’s more to choosing a scope other than magnifying power. Especially if you are planning to buy one for more professional purposes.
Parallax refers to a kind of visual error that is a result of the difference in the position of viewing. As your head moves while viewing a target through the scope, the reticle also seems to move around. This obviously causes problems sighting the target and hitting it accurately.
This is more of a concern when working in higher magnifications. Most scopes with high zoom offer a parallax adjustment knob on the side of the tube.
You can learn more about parallax here:
Scopes come in two focal plane options. FFP (First/Front Focal Plane) and SFP (Second Focal Plane). There’s one major difference between the two.
As you zoom in on your target, the size of the reticle changes on an FFP scope. Whereas on an SFP scope, the reticle size stays constant.
The benefit of FFP scopes is that you don’t have to calibrate the scope settings every time you change the zoom. Since the reticle has already adjusted in size to the zoom.
FFP scopes are great for long range shooting where quick follow-up is important. FFP scopes are more expensive than SFP options. You can learn more about focal planes and great options for either scope type below:
Eye relief is the air gap between the rear lens of the scope and the eye of the shooter. It's a range within which the target can be clearly seen (generally a few inches). It can either be constant or change with magnification.
Scopes with the most eye relief are called scout scopes. Long eye relief is also a must when working with heavy recoil calibers. Otherwise, the rebounding rifle can cause the scope to hit the shooter in the eye and cause injury - known as ‘scope eye’.
Sights without magnification have unlimited eye relief so this is not of concern.
Read more about Eye Relief here!
Mounting Your Optics
Mounting a scope or a sight requires a mating of mounts and rails. Rails can be a variety of designs: Picatinny, Weaver, and others.
Some sights come pre-attached with mounts that directly mount on rails. Scopes can either be mounted using a single piece mount or two-piece scope rings. Each of these has their own benefits and are available in several different designs. Scope mounts are available in different heights (low, medium, and high) and will be appropriate depending upon the diameter of the tube and objective lens size.
Learn more about the concepts of mounting here:
- Scope Mount Types
- Scope Mounting Height - What you Need to Know
- Best Scope Rings
- Quick Detach Scope Mounts
- Picatinny vs. Weaver - Interchangeable or Not?
- Sight Pushers - What to Look For
Zeroing & Adjustment
Zeroing is a very important part of using a scope. It simply means that you align the scope and the barrel of your rifle so that their line of sight intersects at a specific distance.
Say you zero your scope at 100 yards. It means that the bullet fired from your rifle will hit the exact spot you see at the center of the reticle in your scope. Now you can make further calibrations taking this as a reference point.
Equipment such as scope bubble levels and laser boresights can help with zeroing the rifle or handgun. Turrets are used to make proper adjustments for changing values.
Learn about zeroing, adjustments, and related considerations here!
- Bubble Levels - How They Help
- Laser Bore Sights For Accurate Zeroing
- How to Zero A Scope
- Scope Turret Considerations
- Magnification vs. Distance
Scopes and sights are not always plain and simple. There are other more advanced variants designed for specific situations and applications.
For example, some scopes and sights offer compatibility with night vision optical devices for use in the dark. Then some scopes have thermal night vision and sense the heat from objects to sight them in absolutely dark conditions and at longer ranges.
Here's some of the articles we have that cover each these specialty alternatives & additions:
- Best Night Vision Scopes
- Offset Iron Sights: How Useful Are They?
- Best Thermal Scopes
- Clip On Thermal Scopes
Spotting Scopes & Binoculars
Spotting scopes are specialized scopes that are used for watching objects at very long ranges. These scopes are generally used by spotters who accompany snipers on the field. Spotting scopes help identify the target and some more advanced versions help with estimating factors like range, wind, and more.
Binoculars serve a similar purpose: spotting targets, scouring landscapes, and surveying terrain. These aren’t as extensive in magnifying power as spotting scopes.
Learn more about these options below:
- Spotting Scopes vs. Binoculars - What's Best for You?
- How to Pick A Spotting Scope Tripod
- Best Spotting Scopes
Reticles are the reference point inside the scope tube that allows the shooter to aim at the needed point of impact. From being merely a twist of two tungsten wires (or hair in the early days - hence the name crosshairs) to very advanced designs that can be illuminated and allow hitting targets on the move without much need for turret adjustments.
Reticles can be calibrated in Mrad (mil-radians) or MOA (Minute of Angle). Mrad is preferred by the military and many pro shooters. But either of these is fine if you are comfortable with one.
We discuss reticles in more depth here:
When is it Time for a New Optic?
There will be quite a few circumstances when you’ll have to consider upgrading your optic. It could be due to wear and tear of your current setup or a necessity due to a different use-case.
Read on to learn about when these situations may arise and what to consider!
Increasing Range or Switching Calibers
A low power scope is obviously meant for short range. Plinking, hunting, or range use is good for such scopes. But if you are planning to increase your shooting range, switching to a more powerful scope with a better reticle is essential.
As far as sights are concerned, they don’t offer magnification. But some models out there can be coupled with a magnifier to get some level of zoom. For example, the Aimpoint Pro can be coupled with a 3x or 6x flip magnifier.
Similarly, switching from a centerfire to a rimfire weapon and vice versa may call for a change of optic. No doubt, you’ll notice the difference and understand the need to switch to something more resilient.
Turrets Become Mushy, Wobbly, or Loose
The turrets on the scope are designed to be crisp and often equipped with a mechanism to provide the haptic feedback to confirm you've changed calibrations. As a scope (or sight) grows older, these turrets start to get mushy and lose that satisfying and distinguishable ‘click’.
This issue can sometimes be addressed by cleaning and greasing the knob innards. But if it doesn’t go away, you need to contact the warranty department or get a new scope.
Battery Life is Dwindling
Some users realize sooner or later that their scope/sight battery dries out faster than expected. So upgrading to a model with more life overall and auto-off features can be a reason to change.
Can You Find a Quality Optic That’s Affordable?
Absolutely. Not everything that is of great quality has to be insanely expensive.
If you are looking for a high-quality affordable scope, go for Leupold, Burris, or Vortex. For FFP scopes, go for Primary Arms or Monstrum Tactical scopes.
Some sights from Vortex and Sig Sauer offer a great balance between quality and cost.
Holographic sights will always be expensive and so will be sights from companies like Trijicon and Holosun.
While scopes help with magnifying distant targets and shooting them with precision, sights are quick to target acquiring optics designed for short range and shooting with both eyes open. The options are vast for either, so use this guide to help you navigate to the topics you need to help narrow down the selection.
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