Choosing Spotting Scopes By Distance (100, 200, 300 & 500 Yards)

If you’re considering upgrading your optics and the binoculars no longer hold the power you need, it’s time to move on to a spotting scope. With so many scopes to choose from it can be confusing knowing which scope to buy. In this article we’ll run through all of the basics and give you all the information you need to make the best choice of spotting scope for your needs.

Probably the most asked question we hear concerning spotting scopes is what magnification will I need? The answer to which isn’t that easy, there are many things to take into consideration before buying a scope. So let’s start with the basics.

What Do The Numbers On A Spotting Scope Mean?

Whether you’re looking at binoculars, a rifle scope or a spotting scope, they’re all identified in the same way. The level of magnification and the diameter of the objective lens. Let’s look at a typical scope size;

20-60×60 Spotting Scope

Everything before and including the X indicates magnification. In this case there’s a hyphen between the first two sets of numbers which indicates a zoom lens. So the magnification on this particular scope starts at 20 times and zooms to 60 times (the x indicates times). In plain English everything viewed through this scope starts at 20 times larger than through the naked eye, and zooms to 60 times larger than with the naked eye.

This particular model has a zoom to increase the level of magnification, not all scopes have that feature, but more on this later.

The numbers after the X indicate the diameter of the objective lens in millimeters, in this case 60mm. The size of the objective lens is important because the objective lens is the only way any light can enter the scope. Which effectively means the only way any image viewed through the scope can get illuminated enough to see it, is through the light that enters through the objective lens.

So the larger the objective lens diameter, the brighter the objects viewed through the scope will appear. However, as the size of the objective lens increases, so does the overall weight of the scope. A large objective lens weighs more, which means the weight of the scope is dependent on the size of the objective lens. Some spotting scopes will have numbers like this;

8×25 Spotting Scope

This model has a fixed magnification of 8 times, so anything viewed through the scope will appear 8 times larger than with the naked eye. But there’s no zoom so 8x magnification is the limit on this model. The other number after the X is always the size of the objective lens diameter in millimeters (in this case 25mm).

A Quick Word On Magnification

Now you can understand what the numbers on the scope mean. Let’s clear up a few points and misconceptions about magnification. We often hear that the higher the magnification the better, and up to a point that’s right…Up to a point. You see, although having a magnification of 60 times the naked eye sounds great, the reality is somewhat different. There are a few disadvantages to increased magnification.

Firstly any magnification above 10x will cause a handheld scope to show a blurred image. This is due to human physiology and the way we shake slightly when holding anything for extended periods of time. So any scope with a magnification of higher than 10x will need to be supported on a tripod. But that’s not all, below are 5 reasons that 60x magnification isn’t as good as it seems.

1. Image Instability
   This is that shake we spoke about, sadly without a tripod the image will be so blurry as to be incomprehensible.
2. Narrow Field Of View
   The field of view is the width of the image you can see through the scope. As you increase magnification you lose the width of the image.
3. Darker Image
   To see the image clearly, you need the light to be spread over a greater part of the image.
4. Loss Of Image Quality
   Due to atmospheric conditions like hazy sunlight, slight mist etc, all of these atmospheric conditions affect the quality of the magnified image.
5. Optical Integrity
   Unless you are going to purchase a top of the range scope, the image will not appear to be sharp, crisp and clear at high magnification.

Spotting Scope Eyepieces

While on the subject of magnification, some scopes are supplied with a fixed eyepiece like the second example we gave (8×25) these tend to produce clearer images but at lower magnification levels. Others like the first example we gave have zoom eyepieces (20-60×60) which give a choice of magnification levels and are pretty good at the lower end of the zoom but do lose clarity as the magnification increases, especially the cheaper models. It really is a case of you get what you pay for.

Other Problems With Scopes

Sometimes even with top quality scopes, the image isn’t clear. This is down to weather and climatic, atmospheric conditions and there’s nothing you can do about it. Sometimes the weather’s just against us and that’s that. On days like that it’s best to revert to your tried and tested binoculars.

Yes you won’t have such a great magnification range, but at least you’ll see something. Spotting scopes can struggle when up against wind, humidity, and heat mirage, so to see really crisp clear images you do need the weather to cooperate too. So although a decent spotting scope is a great piece of kit and can really enhance your viewing capabilities, they can’t replace a good pair of binoculars. 

A spotting scope should be used in conjunction with, and not instead of binoculars.

What Is The Most Important Consideration When It Comes To Spotting Scopes?

So if magnification isn’t the most important part of a spotting scope, what is? The main reason for using a spotting scope or a pair of binoculars is enhanced, magnified, clear images. One of the main problems encountered with spotting scopes is chromatic aberration especially at high magnification and longer distances.

What Is Chromatic Aberration?

Chromatic aberration is basically the inability of a lens to focus all colours of light at the same point. It shows as colour fringing at the edges of dark and light parts of the image. To combat chromatic aberration the scope manufacturers use glass which is usually combined with flourite  which creates extra low dispersion glass often referred to as E D glass. 

Improved Light Transmission

For a clearer, brighter, sharper image scopes need excellent light transmission properties. Better light transmission is achieved by using top quality optical glass like E D glass for the lenses and BAK-4 glass for the prisms. 

BAK-4 Glass

This is the top quality optical glass with the least imperfections and is used in top quality spotting scopes and binoculars. This ensures less chromatic aberration, improved light transmission and better, clearer images.

BK-7 Glass

This glass is still high quality optical glass but has slightly more imperfections than BAK-4 glass and is used at the lower end of the price range scopes.

Lens Coatings

Another way to improve the light transmission is to coat the lenses with coatings designed and formulated to reduce glare and of course cut down on chromatic aberration. There are levels of coatings and any is better than none but we believe that FMC or fully multi-coated lenses offer the best light transmission. FMC means all lenses inside and out have been fully coated with multiple layers to reduce glare and improve light transmission.

What Size Spotting Scope Do You Need?

Now you have a more rounded view of the way spotting scopes work and what the numbers mean etc let’s get on with which size scope you need. It’s always going to come down to power when it comes to buying a scope, because that’s how they’re classified but remember light transmission is more important and as such you should always opt for the best brand of scope your budget will allow. But as a rough guide;

Recommended Spotting Scopes For 25 to 75 Yards

If you need a scope that will work between 25 to 75 yards, then you’ll probably do just as well with your binoculars. You might prefer the stability a tripod can offer but again, binoculars have adaptors for tripods. But if you really do want a scope for the 25 to 75 yard range, go for a lower magnification level and a better quality scope.

That will give you the best of both worlds clarity of images, close focus and better quality optics at a price that won’t break the bank. Go for;

• Lower Power
  8-24x, 10-25x, 12-30x
• Lens Coatings
  Fully Multi-Coated (FMC) is best.
• Close Focus
  Less than 25 feet is preferable; this will allow you to see objects closer but still in focus.
• Large Objective Lens Diameter
  Remember the larger the diameter of the objective lens, the brighter the image will appear through the scope.

Recommended Spotting Scopes For 100 Yards

Realistically any scope for use under 100 yards high magnification and a large objective lens are less important. And most budget scopes are capable of this. Spotting scopes for 100 yards require a magnification of around 20 to 40x so;

• Low Power
  10-30x, 18-36x, 15-45x, 16-48x
• Lens Coatings
  FMC (fully multi-coated) lens
• Tripod
  To maintain a steady image a tripod will be required.

Recommended Spotting Scopes For 200 Yards

At the 200 yard range you’ll need high power and good clarity as well as high resolution. Look for;

• Higher Powered
  20-40x, 20-60x
• Lens Coatings
  Fully multi-coated (FMC).
• Tripod
  You will definitely need the stability of a tripod to see clear images.
• Prism Glass
  BAK-4 is best.

Recommended Spotting Scopes For 300 Yards

As a general rule of thumb, for high distance spotting better quality optics are required. For 200 to 300 yards you’ll need more magnification and more clarity of image. This distance viewing requires better quality scopes which come with a higher price tag. Look for;

• High Power
  20-60x, 20-80x
• Objective Lens Diameter
  60mm to 80mm
• Lens Coatings
  Fully multi-coated (FMC).
• Prism Glass
  BAK-4
• Tripod
  An absolute must at this distance.
• Dual Focus
  To fine tune the clarity of the images, fast focus or dual focus systems will work best.

Recommended Spotting Scopes For 500 Yards

At the 500 yard range, you’ll need top quality lens coatings, top precision optical glass, larger objective lens diameter and higher magnification. Look for;

• High Power
  20-60x, 20-80x
• Objective Lens Diameter
  60mm to 80mm
• Lens Coatings
  Fully multi-coated lens (FMC)
• Prism Glass
  BAK-4
• Lens Glass
  Extra-low dispersion glass (ED)
• Tripod
  As with all high magnification scopes a tripod is necessary for a stable, clear image.
• Dual Focus
  Once again you should consider fast focus or dual focus systems to fine tune the clarity of the image.

Recommended Spotting Scopes For 1000 Yards

The ability to see crisp sharp, clear images at 1000 yards takes a special spotting scope. You won’t be able to pick up a scope with this capability in the bargain basement. It will need every enhancement feature available to spotting scopes. Look for;

• High Power
  20-60x, 20-80x
• Objective Lens Diameter
  80mm and above
• Lens Coatings
  FMC (fully multi-coated) lens
• Prism Glass
  BAK-4
• Lens Glass
  Extra low dispersion ED glass
• Tripod
  A strong supportive tripod will be needed to take the extra weight of the larger objective lens diameter.
• Dual Focus
  Fast or dual focus systems will be a definite must to fine tune the optics at this distance. You might want to consider a ranging spotting scope.

What Is The Best Size Spotting Scope?

As you will already have gathered, whilst magnification plays an important part in the performance of the spotting scope, the quality of the glass is of greater importance for the clarity of the image seen.

Of course, we all want a bargain, but you really can’t skimp on quality when it comes to optical equipment. The most inexpensive scopes work well up to around 100 yards, but there is an incremental price increase per every 100 yards extra. Consider just how much distance you need to be able to see and then choose the best quality you can afford. Taking into account optical quality, image brightness and then magnification.

Waterproof Spotting Scopes

A decent spotting scope will be a wise investment and to keep it in top quality condition you should think about buying a waterproof scope. The manufacturers purge the lens tube of air and replace it with an inert gas like argon or nitrogen. This makes the scope fog proof and dust proof too. They also use a system of O rings to create a waterproof barrier so nothing gets inside the scope that shouldn’t be there.

To find out more about the waterproofing code system set up by the industry follow this link.

Frequently Asked Questions