Bull's-eye!

8 2010 June 12 894 1

MicroSight-equipped sight

Sights, equipped with the latest optical system based on zone plates, will allow the shooter to simultaneously keep in focus both the front sight and the distant target.

Try to shoot a rifle at the target meters, say, with a hundred. If you are not a professional, you are unlikely to fall into it at all. If a professional and even make allowances for the wind, it will be a great success to hit the bull's eye.

The most difficult and most important thing when shooting is, of course, to aim correctly. To combine a remote target with a front sight is not an easy task, even from the point of view of optics. It is necessary to simultaneously keep attention on the remote (target) and close (front sight) object, and the eye, like any other optical device, is unable to focus together on this and the other. Either that or the other will be blurred.

Concentric rings of the zone plate allow you to keep simultaneously and distant objects in focus

Get rid of this seemingly unsolvable problem will allow technology MicroSight, which is developed by an American engineer David Crandall (David Crandall). Its essence is to install on weapon on the line of aiming of a tiny, coin-sized, transparent disk, allowing the arrow to keep both distant and close objects in focus at the same time. And the main secret is, of course, in the disc itself.

David Crandall is a keen shooter trying to hit a target from 100 meters using his new aim.

It is nothing more than a Fresnel zone plate, a glass disk consisting of a set of concentric circles of strictly defined diameters. Such a zone plate acts almost like a lens, although the principle here is different. In a conventional lens, the rays of light are refracted due to the difference in the speed of light inside it and in the air, and the Fresnel lens works due to diffraction, i.e. changes in the direction of the beam as it passes through an obstacle or aperture, the dimensions of which are comparable with its wavelength.

Crandall proposed using a zone plate, consisting of a set of glass rings, transparent and translucent. Light passes through the transparent rings without changes, allowing you to focus on distant objects. And on the borders of translucent rings, diffraction occurs, focusing the light from objects close to them. As a result, the main thing turns out: the ability to simultaneously clearly see both a distant target and a close fly.

Of course, today there are alternative solutions for sights. But most of them are complex devices, often (like holographic sights) requiring even electronic components. Compared to them, MicroSight looks very inexpensive, simple and reliable, although not as accurate. And reliability and simplicity are sometimes more important than accuracy.