The Relation of Magnification and Distance

You sighted a bird with your bare eyes from about 30 yards from you. Then the bird flies further from you to about 60 yards and the bird seems to have reduced in size (almost half size). So you decided to use a magnifying device to view the bird from 60 yards and you see that the bird is now just like the same size you saw it when it was 30 yards from you. Now, that’s the influence of magnification and distance.

The image distance has a good influence on the magnifying power of your scope. So, have you ever wondered what the relation of magnification and distance is in the world of rifle scopes? You will get to find out soon because we’re all about that in this post.

Understanding the Idea Behind Magnification

Before we look into the relation of magnification and distance, let’s first have a good understanding of the idea behind magnification.

So, when we talk about the magnification of the scope, we’re referring to the number of times the view you see through your rifle scope has been increased. The magnification number is usually written as a number that is followed by ‘x’ which implies how many times the number is multiplied by.

For instance, you can have a magnification value to be ‘4x’ and this implies that what you see through the scope is 4 times that of the actual image.

Ideally, any scope you purchase should come with a type of specification or identification number. This will let you know the magnification range of your rifle scope. For better understanding, the specification number can come as 6.4x 50. So, we can decipher that that particular rifle scope has a set magnification to be 6.4. Then the value that follows is the objective lens which is 50 millimeters and this is measured in diameter.

Now, you may have a variable scope and the magnification for this variable scope is usually different. A better illustration of the magnification of a variable scope is 3.5 – 25 x 50. We can tell from this value that the scope has a magnification increase from a range of 3.5 and can increase up to 25 times. Then the value that follows is the objective lens measured in diameter.

Get to Know the Relation of Magnification and Distance

Magnification is that thing that is on your scope capable of making far object bigger, and the distance is related to a specific target. Now, the distance of the targeted image influences the magnification power of your scope.

The fact is that a scope’s objective lens with a higher magnifying value tends to be great for viewing the distant image. Conversely, a scope with lower magnification is ideal for short range distance (meaning a short focal length tends to have a short range of distance).

As we proceed further into this article, we will also recommend a magnification range that will suit some particular distances. So, keep reading to find out.

Angular Magnification and Linear Magnification

Now, the physical characteristic of what you can see from an object is the angular magnification. This is influenced by the type of lens you have (either thick or thin lens). It is also influenced by other things such as a concave lens or convex lens or the curvature of the lens. Again, it can also be determined if you have a bigger magnifying glass.

Another thing that can determine how your magnifying power works and how it functions is the linear magnification and there are different equations for it. Take for example: it’s possible you find a scope that is made from a thin lens equation due to the thickness of the physical glass.

Therefore, we can see that we can have various lens formula capable of defining and creating the features of a particular lens. And this is solely based off physical characteristics.

Furthermore, the major parts of the various types of lens found in the inner part of the scope all perform 3 main purposes. These various types of lenses can be converging lens, diverging lens, first lens, and second lens. Let’s look at the function they perform below:

The function of the main parts of various types of lens found inside a scope

1.       Helps form image and magnification

Image formation is done when light ray is assimilated by the objective lens. This process generates a refractive index making this reflect light back to generate a virtual image. Now, this virtual image is derived from the actual targeted image. Then the second may now help in producing a final image as well as the focal point to enable a better view for the shooter.

2.     Inverted image magnification

The objective lens produces an inverted image. Then the concave mirror and convex mirror help return the inverted image upright. So, the look-alike of this spherical mirror lens enables you to see the image. This makes the rifle scope kind of identical to a microscope or compound microscope.

3.    Focusing the targeted image

Now we have the ocular lens that helps focus the virtual image making the shooter see clearly through the optic. So, the ocular lens’s diameter influences your eye relief. Take note that eye relief is the distance you give your eye and the ocular lens. You also can also refer to this as focal distance.

Understanding The Magnification of Equation

When we talk about the magnification equation, we’re referring to that thing that determines the image size that you view through your riflescope. It also determines the distance of what you have of the image that has been magnified.

Take note that magnification alone is literally the ratio that we derive from the focal length of the objective lens as well as the ocular’s focal length.

So, the magnification equation will help us know how the image size or object height will vary from the real image being viewed. Let’s take this instance: when you view a particular image with 3x magnification, it will appear like it’s 3 times closer to you. So, when you view an image distance 300 yards away from you, it will appear like it’s 100 yards from you because you’re using a magnifying power of 3x.

The magnification equation will not only tell you how close the object is to you, but it will also show you a bigger picture of the object. Therefore, apart from using magnification to help you get a closer look at the target’s image, it will also give you almost double the size of the actual image.

Recommended Magnification Range That Suit some Specific Distance

Now, let’s recommend some magnification range that can suit certain distances so that you can always get that clear view. So, below are the common shooting distance and recommended magnification for a riflescope:

1.    100 yards shooting distance

Before anything, it’s ideal you take into consideration of the caliber as well as the kind of gun you will be shooting with. So, you will need a magnification of 3x if your shooting distance is 100 yards.

Furthermore, if you’d like to go for a higher magnification or you want your vision to be enhanced more, a scope with a fixed or variable range of 3x-9x should be fine. This magnification range will offer you excellent vision. Also, you won’t have to worry about it slowing down your rifle because of excess weight and there won’t be any unwanted distortion.

2.    200 yards shooting distance

It’s safe to say that the 200 yards shooting distance is one hunting distance presently common in the world of shooting. So, for this distance, 3x magnification can still work and a variable range of 3x-9x is fine. However, the 3x magnification might be a little short. So, we recommend you start with 4x when dealing with 200 yard distance objects.

3.    300 yards shooting distance

A 300 yard distance may be a bit far for many shooters. Therefore, we recommend you start the magnification range from 4x for a 300 yard distance target range. A variable range can be 4x-12x for 300 yards.

4.    400 yards shooting distance

Getting to a 400 yard distance means we are looking at a long distance range in the world of hunting and shooting. Notwithstanding, this 400 yard is somewhat categorized under 300 yards. Therefore, you can still use the same range which is 4x-12x for a 400 yard shooting distance.

5.    500 yards shooting distance

500 yards is definitely an extreme distance when it comes to hunting. Although most shooters rarely go farther than 300 yards not to mention 500 yards, we still have some competitive shooters that ply this distance range.

Therefore, when it comes to shooting with 500 yard distance, going higher is needed. Hence, we recommend a magnification range of 6x-18x for 500 yard target range.

6.    1000 yards shooting distance

Now, let’s go extra high with 1000 yard shooting range. Judging from this distance range, we can tell that this is weight out of range for many shooters. Even competitive shooters that do long range find this 1000 yard to be extreme.

However, you may still want to dive into this extreme range and it’s crucial you get the appropriate magnification range. So, to get that accurate shooting for 1000 yards, we recommend you go as high as a 12x-24x magnification range to have a clear image view.