although Reflex is also called "sight", its optical system is relatively simple, and there is usually no magnifying system, so there is no image reversal system. Its principle is as shown in the above figure: the concave surface of the analyzer is plated with one or more layers of chromatographic optical films, and the light emitted by the illumination system passes through the reticle and then forms aiming marks such as dots (or rings) on the analyzer, which are reflected as parallel light and enter the human eye. At the same time, the human eye sees the target through the analyzer, and when the aiming marks overlap with the target, the aiming is completed. This kind of sight has another name-Red dot sight, because the aiming mark of this kind of sight is usually a red or bright orange light spot. Of course, not all reflective sights use light spots, and some will be crosshairs, auras and even other shapes.
The curved surface of the analyzer of a high-precision spot sight is very particular, because it must ensure that the aiming mark is on the impact point even if the shooter's eyes are not directly facing the axis of the sight. The following two pictures further illustrate:
The relative position of the sight and the camera door in the left and right pictures better illustrates the characteristics of the reflective sight. After the sight is zeroed, it can be aimed from different angles, so it is especially suitable for rapid aiming in melee.
Due to the above advantages, the reflective principle allows the eyes not to aim at the axis of the sight when aiming, so the aiming response is faster than that using the light guide rod principle. This makes the reflective spot sight very popular. After entering the 199s, the armies of all countries began to attach importance to the tactical value of the sight and equipped a large number of troops.
the aiming mark on the spot sight is generated by the illumination system on the sight. There are many ways to form a light source, such as power supply, natural light or radioactive isotopes such as tritium, promethium and so on. The light spot generated by the power supply is easy to adjust, and different brightness can be adjusted according to different use environments; Natural light is a way to save energy, but it will reduce the effect when the lighting conditions are not good; Radioisotopes can work for many years without replacing batteries, and the effect is better when used at night. However, radioactive materials should be carefully selected. Tritium gas, which is popular at present, is said to have low radiation, so people who use this sight for a long time are safer than those who receive X-ray examination once or twice a year.
reflective spot sight usually has two structures, one is cylindrical and the other is window. The window structure is relatively simple, but the analyzer is completely exposed; The cylindrical structure looks very similar to the telescopic sight. The analyzer is wrapped in the cylindrical mirror, and there are objective lenses and eyepieces in front and back for protection. At present, there are some products that combine spot sight and telescopic sight, that is, spot sight with magnifying function, such as ACOG of Trijicon Company and 5 2X of Aimpoint Company.
you may not be familiar with ACOG aiming in COD4. Give you an introduction:
ACOG, full name is Advanced Combat Optical Gunsight. This series was founded in 1987 as part of the ——ACR project, an advanced American combat rifle. ACOG is a combination of telescopic sight and spot sight, which not only has the function of magnification, but also has the function of binocular rapid aiming.
the shell of p>ACOG is made of aviation aluminum, which is firm, waterproof, cold-proof and corrosion-resistant, and can withstand various pressures and impacts of diving depth and field use while keeping the accuracy of the sight unchanged. ACOG's aiming division adopts the dual lighting system patented by Trijicon company, natural light and tritium light. Natural light is absorbed from a lighting system made of optical fiber at the top of the sight, and then reflected to the shooter's eyes through the reticle to form aiming marks. The exact location of the tritium light source is not marked in the picture below, but I guess it is on the base of the sight, directly below the natural lighting system. The amount of light emitted by the pale yellow standard mark depends on the light source conditions of the environment and can be adjusted automatically.
ACOG has an automatic zoom function called BAC(Bindon Aiming Concept), that is, when the weapon is moving rapidly, the magnification of the sight is doubled, and when the weapon stops moving or moves slowly, the sight automatically returns to its original magnification. Take TA31 as an example, that is to say, it is four times when it is stationary or moving slowly, and it is one time when the shooter moves quickly or turns to the aiming direction quickly. Some people have speculated that it may use automatic zoom functions such as shifting the center of gravity or hydraulic pressure. In fact, ACOG does not have any zoom function inside. It uses a high-brightness aiming point and a new prism image system, so that the clear image of the aiming point in the mirror and the clear panoramic image obtained by the naked eye can be transmitted to the brain at the same time, thus avoiding the influence of the forced choice of the human brain on aiming/observation, and enabling the aiming eye (that is, the eye that observes through the aiming mirror) and the naked eye to work at the same time. Therefore, it is one of the selling points of ACOG to keep aiming with both eyes at all times.
The so-called "mandatory choice of human brain", in general, the human brain can only accept a clear image from a focal distance at the same time, so. When using the traditional optical sight. Because the focal distance of the traditional optical sight is different from that of the naked eye. So the brain can only switch between two eyes. Select one of them to observe. And the other eye will be forced out of focus because of the different focal distance, for example. You observe with your left eye through the optical sight, and at this time your right eye (naked eye) will be out of focus, and vice versa. If you observe with your naked eye, your left eye observed through the optical sight will be out of focus, so you can't quickly look at the target in the field of view. In particular, it will greatly affect the reaction speed to distinguish small targets that are moving or have little difference from the background.
the main advantage of using the sight with BAC function is that the aiming eye can still clearly see the image of the aiming point while obtaining a clear panoramic image with the naked eye (that is, the brain can receive two clear images at the same time). Therefore, the brain will be able to quickly switch/combine between the two acquired images, that is, you will be able to make the sight accurately capture the target and start shooting while finding the target with the naked eye, or you can quickly switch to the aiming eye to obtain a target image magnified by the sight for accurate aiming and shooting. It is not necessary to switch between the eyes first, and then get a clear image, as when using the traditional optical sight, and then find the target, aim and shoot. Therefore, the efficiency of target discovery and capture will be greatly improved, because everything will be done at the same time.
This is not a super space technology, but a very simple, smart and practical design. However, this function is not effective for everyone, such as those whose eyesight is quite different (for example, if the left eye is 2. and the right eye is .8, the benefits of BAC cannot be realized).
ACOG's aiming mark has a variety of shapes and colors for buyers to choose from, namely triangle, dot, inverted v and crosshair.