Like a telescope, the sight can zoom in on the distant scene and magnify the object to a certain multiple. But optical sights and telescopes are two different concepts of optical instruments. We all know that telescopes use convex and concave mirrors to complete their work. So what is the working principle of optical sights? How does it work? Why optical sights Can you aim the object?

Because both the bullet and the scope can be regarded as a ray, the two rays in the same plane and in one direction are either parallel or intersecting. In fact, the point in the scope is exactly the ray of the scope and the bullet. The intersection of the rays, as shown in Figure 1, you can see that the bullet’s parabola and the line of sight have two focal points, and are the target sights.

But because the distance of the target is different, the intersection of the ray of the scope and the ray of the bullet may not necessarily fall on the target. This requires adjusting the distance of the intersection of the ray of the scope and the ray of the bullet. In order to adjust, it is necessary to adjust the installation angle of the scope according to the target distance. If you want to shoot accurately, you must also consider the influence of the wind direction, which is the so-called correction.

First, the trajectory is a parabola, not a straight line. It is like the trajectory of the water flow when watering with a hose.

Second, the distance of the firing range is related to the firing angle. The greater the firing angle of the muzzle or muzzle is within 45 degrees, the longer the firing range.

Third, the line of sight is a straight line, which can be directly above the gun body, or on the left or right side of the gun body.

Fourth, to make the gun or artillery shot accurately, adjust the angle between the barrel and the line of sight. The angle between the line of sight and the barrel is different for different ranges. For firearms, the line of sight of the mechanical sight is determined by the front sight and the rear sight. Generally, the sight can be moved up and down to adjust the angle between the sight line and the barrel. The line of sight of the scope can be determined by the range setter or by the division on the reticle in the scope.

Fifth, in the actual use process, the situation is changeable, the target may be moving, and there may be the influence of wind deviation. At this time, it must be corrected to be accurate. I won't say much about the specific correction method.

Sixth, the trajectory is not necessarily in the vertical plane. 1. For projectiles with stable rotation, there will generally be a deflection to the right. The farther the distance, the greater the deviation, and it will produce a downwind deviation. 2. For stabilized projectiles on the rear wing, headwind deviation will occur.

Seventh, the trajectory is not fixed, even if the firing angle remains the same, and the type of ammunition or charge remains the same, the trajectories cannot overlap, but can only be similar.

(This paragraph is the principle of imaging, don’t look at it) The main function of an optical sight is to use an optical lens for imaging, superimposing the target image and the aiming line on the same focus plane, even if the eye is slightly offset, it will not affect the aiming point. An optical sight has at least three optical lens groups, one is the objective lens group (Objective Lens), the other is the corrector tube group (Erector Tube), and the eyepiece group (Onicular Lens), and there may be other lens groups. The objective lens group is responsible for collecting light, so when the objective lens is larger, the sight in the scope should be brighter. The eyepiece group is responsible for changing these rays back to parallel rays so that the eyes can focus and create the largest field of view; while the correction lens group is Correct the image of the objective lens from upside down and left and right to the correct direction, and adjust the magnification. The line of sight can be located at the first focus plane before the correction lens group, or the second focus plane after it, and the wind deflection adjustment knob, height adjustment knob, and magnification ring are all used to control the correction lens group Left and right, high and low, front and rear positions. There may be as many as 9 lenses in the body of a high-grade sight. Through proper coating, the light transmittance can reach 95%.