Red dot sights – classification and usability

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Red dot sight

Introduction

In recent years, the term ‘red dot’ has become widespread in the shooting market. It is used for devices that feature an illuminated dot, most commonly in red colour, allowing for accurate and precise aiming at a target. Devices of this type were first used by the military and police. Today, these are used by sports shooters and hunters as well. What red dot sights of all types have in common is the presence of an illuminated dot instead of a standard reticle. Because these devices are almost exclusively limited to daytime use, the illumination must be powerful so that it can be used during strong daytime brightness and even in situations when there is snow or the sky in the background. The first devices of this type already offered a wide field of view but featured a magnification slightly above 1x. Today, red dot sights come with a 1x magnification, allowing convenient use with both eyes open. A great demand for these optical devices brought about accelerated development in this field. Today, there are two notable red dot sight types available on the market – open reflex red dot sights and tube red dot sights. Tube red dot sights can be further divided into small tube sights and full tube sights. Because of red dot sights’ popularity, riflescopes’ manufacturers have decided to come up with their own solution. The outcome was a variable magnification riflescope where the user could set the magnification all the way down to 1x. This resulted in a wide angle of view, which is why these have since been referred to as ‘wide-angle riflescopes’. To make the product competitive in the red dot sights market, the manufacturers added an illuminated dot in the centre of the field of view. Because of this feature, the term ‘red dot’ is often inclusive of wide-angle riflescopes. In the following chapters, characteristics of individual red dot sight types will be listed and discussed.

Red Dot Sights
Different kinds of red dot sights and a wide angle riflescope

The usability of a red dot sight

Some hunters, mostly those, who haven’t tried these devices out yet, still have second thoughts on the use of red dot sights. Aiming at targets nearby with riflescopes is difficult because of the limited field of view, especially if these targets are in motion and are to be aimed at in stressful situations. In such circumstances, iron sights and red dot sights will be much more efficient. Using iron sights is a reliable method; nevertheless, it cannot be equated with red dot sights in terms of versatility.

The first problem that comes with the use of iron sights is the inability of the user’s eyes to focus on the front sight, rear sight, and target at the same time. Because of this, plenty of shooters use iron sights in a way that they only have the target in focus, having the front and rear sight out of complete focus. This problem is most evident with people that have eyesight issues. Another drawback is the reduced field of view – most hunters aim at a target using only one eye and closing another. With red dot sights, this problem is eliminated as the user can conveniently use them with both eyes open. With one of the eyes, the user looks directly through the lens, seeing an illuminated red dot. The other eye is also observing the target, not through the lens but freely. This way, both eyes are focused on the target while the field of view is the same as during a normal observation. Our brains merge images seen through both eyes, resulting in a combined image of both the illuminated dot and the target. The user takes the shot when the aiming point is at the correct spot on the moving target. This system provides for an efficient aiming and shooting, especially with fast moving targets.

Red dot sights operate at 1x magnification, allowing use with both eyes open. Because of this, our field of view is not reduced, enabling a more precise evaluation of the game. During driven hunts, red dot sight users can observe more animals at once and decide which one is the most appropriate to be shot. It can be concluded that red dot sights give users the possibility of an ethical shot. Additionally, a better overview of the surrounding area will result in fewer bullets ending in trees or piercing trees as with iron sights’ use.

Even though red dot sights were fundamentally designed to be used on rifles, they have lately been gaining in popularity among shotgun owners. Because of this, many red dot sight manufacturers started producing red dot sights with a circle dot reticle. The circle’s diameter is compliant with the usual scatter of pellets on 25 m.

Red dot sights and the parallax error

The quality of each sighting device is, principally, dependent on the possibility and success of correcting the parallax error at various distances. Many hunters are still perplexed by the term. Parallax error is present when the focal plane of the object seen through the scope is offset from the reticle. In practice, the error is present when changing the position of the eye appears to have an effect on the position of the reticle on the target. Red dot sights usually have the parallax set so that the error equals zero at 50 m. Riflescopes with a variable magnification, on the other hand, usually have the parallax set at 100 m (the exception are riflescopes that have an adjustable parallax). With devices that have a fixed parallax, the quality is measured primarily in how negligible this error is at various distances. High-quality red dot sights display this error at such a minimal rate that the dot appears to be on the same spot from 15 m onwards, regardless of the eye position in front of the device. The cheaper devices, however, have a bit more problems in this field.

Reflex sights

This is the first out of the two most popular red dot sight constructions. Among these, we find the smaller, most compact optical sighting devices in the industry. Lately, bigger variants of reflex sights have been introduced, but most manufacturers still produce the compact type. Reflex sights consist of a glass element (window, lens) on which a red dot is projected by the LED. Dimensions of the implemented window vary, but a window with dimensions 25 x 20 mm tends to be the most popular for hunting applications. The prime advantage of reflex red dot sights is their size which allows them to be mounted on all sorts of rifles, adding no notable weight. They are also extremely popular among handgun users. High-quality products of this type usually have no issues with the parallax error. Additionally, some are equipped with a sensor with the help of which the intensity of the dot is regulated based on the ambient lighting. Those that are made of one piece are waterproof. The lack of waterproofness was one of the major problems that these red dot sights once had, but now many manufacturers have already eliminated this issue. Some cheaper products, however, can still easily get penetrated by water, ruining the user experience. As stated, size is the first advantage of these devices. The second one is the intuitive use – our eyes barely see the hood of the lens when we aim at a certain object. With some practice, one can train their eyes so that they don’t notice anything but the dot at all. The biggest advantage, even with high-quality contemporary red dot sights, is their intolerance to rain and snow. Even with waterproof reflex sights, water can easily get in between the diode and the lens, deforming the definition of the dot. If this happens, the device must be thoroughly wiped with a cloth. The cleaning procedure can get quite frustrating, which is why some hunters dislike using these in adverse weather conditions. In rain and snow, wide-angle riflescopes and tube sights are a much better option. Reflex sights are a great choice for driven hunts or aiming from a hunting stand but will not be as persuasive in rain/snow and on difficult terrain.

Reflex red dot sight VS tube red dot sight

Tube sights

Tube sights are basically riflescopes with a fixed 1x magnification and an illuminated dot, bright enough to be used in daylight. As the technology in this field improved over time, manufacturers could gradually squeeze the components into a more compact frame. Today, some of these are almost as compact as reflex sights – these are called small tube sights. Their advantages over reflex sights are predominantly in the optical performance which is on a higher level. Furthermore, they are far more robust and will not disappoint even in adverse weather conditions. Because of this, they are extremely popular with military and police. Because they are optically powerful, the definition of the dot is shapelier – the dot is nicely rounded and not as glaring at higher intensity levels as the one projected in reflex sights. Even though many manufacturers have found out how to make these more compact, the disadvantages of tube sights are still size and weight. As much as the manufacturers try, they cannot compete with reflex sights in terms of compactness. These are a perfect choice for hunters who hunt on difficult terrain with lush vegetation. In such occasions, the robustness of tube sights cannot be matched.

Tube Red Dot Sight
Tube Red Dot Sight

Riflescopes

Some riflescopes can also be used in the same fashion as red dot sights. This trend came to use when the manufacturers were able to enhance reticle brightness to the point where it was still visible during daytime brightness. Furthermore, the variable magnification on the riflescope had to be adjustable down to 1x, allowing the user to look through with both eyes open. Both these features cannot be found in the affordable segment of hunting optics – wide-angle riflescopes with a daytime bright red dot are usually priced 700 € and above. Some manufacturers of affordable optics incorrectly specify their wide-angle riflescopes, stating that it features a 1x magnification when the magnification is really 1.1x. This is the topmost magnification where the user can still look through the scope with both eyes open but it can already be uncomfortable for some. Wide-angle riflescopes have issues with parallax compared to red dot sights. In most cases, the parallax is fixed at 100 m, making the parallax error more evident when shooting at short distances. Wide-angle riflescopes with an actual 1x magnification and a day-time bright red dot that can be used as an alternative to a red dot sight have one major advantage – variable magnification. Most wide-angle riflescopes allow the user to set the magnification to 6x (some allow setting the magnification all the way up to 10x), allowing accurate shots at medium-to-long distances. The robustness of these devices is usually on the same level as that of tube sights. Wide-angle riflescopes’ field of use is very universal – one can use them to aim from a hunting stand or during a driven hunt.

Wide Angle Riflescope

Conclusion

We can conclude that red dot sights and wide-angle riflescopes are a very useful contemporary hunting accessory. Their usability is most noticeable during driven hunts, where having a great overview of surroundings is highly important. By using a red dot (or a wide-angle riflescope), the hunter can track a moving target efficiently. Furthermore, red dot sights are extremely accurate when shooting at short distances, allowing for an ethical shot. The choice of a red dot has to do with user preference. Some prefer wide-angle riflescopes, others prefer red dot sights. A wide-angle riflescope is a much better choice in situations where the user must switch between short- and medium-to-long distance shooting. Red dot sights, on the other hand, are a much better choice for very short to short distance shooting but will become inaccurate at distances longer than 70 m. Reflex sights are great if you plan to shoot from a hunting stand, while tube sights will perform better on rough terrain.

+/ – Table

  Advantages (+) Disadvantages (–) Notes
Reflex sights + most of these are compact and lightweight; + quick target acquisition; + great eye-box. – Almost useless in rain or snow; – On some rifles, these have a very limited selection of mounts – Optically, these are not as good as tube sights; – The definition of the dot is not as good as with tube sights. The best solution for quick target acquisition on a short range – with these, the eye-box is least sensitive to the eye position.
Tube sights + Better optics than in reflex sights; + quick target acquisition; + impervious to rain and snow; + robust, durable.   – Big and bulky for a red dot sight (some small tube sights are an exception);   A great choice for those who, while hunting, move through lush vegetation.
Wide-angle riflescopes + Great for short and medium-to-long distance shooting; + robust; + impervious to rain and snow; + filled with dry nitrogen which prevents internal fogging; + There is still a reticle in case the battery dies. – Small eye box; – Parallax usually fixed at 100 m; – Extremely difficult to use at very short distances, such as 10 m; – usually quite expensive. Affordable wide-angle riflescopes, priced under 700 €, usually do not have a daytime bright red dot and a real 1x magnification.   A great choice if you are going to be shooting not only at short distances but also at distances up to 250 m (depends on max. magnification)  

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