How To Choose Red Dot Sight
The red dot sight is generally a military equipment. Very simply put, it is a tiny red dot right at the center of the line of sight, which helps to aim and shoot with significantly greater accuracy. The standard mechanism of a red dot sight is usage of a red light-emitting diode (LED) right in the center of collimating optics. This causes a dot-sized illuminated circle to appear that is aligned with the line of sight of the weapon, and it is parallax free. That means the position of the red dot is independent of the shooter’s eye movements, and hence provide very high shooting accuracy. Nowadays, not only the military and the police use the red dot sight, target-shooting competitors, hunters have started using this technology very widely.
Unlike most scopes, which can magnify targets, the red dot sightdoesn’t do that. It is more of making the shot hit its target faster rather than with more precision. The larger the dot is, more the ease people find in shooting with high-speed accuracy.
The general configuration for a red dot scope is a tilted spherical mirror reflector, with a LED positioned at its off-axis. The mirror has partial multi-layered silvering which lets all light wavelengths to pass through except the wavelength for red light, which is reflected. The deep red 670 nm wavelength, is the most preferred. Since they are very bright and is highly contrasted with the general background, especially a green background. The size of the dot can be manipulated by an aperture made of metal or polished glass, kept in front of the LED.
Since the red dot scope’s collimated image is truly parallax-free only at infinity, some rectifications need to be done. Compensation is done by keeping the dot right at the center of the red light scope. Some manufacturer’s go to extent of manipulating the configuration to get the red dot sight to focus at a finite distance, which generally does not exceed 25-50 yards.
Red dot scopes fall into two separate categories, depending on configuration designs. The ‘tube’ design is similar to the well-known telescopic sights, with the entire conformation fitted into a long tube mounted on top of the firearm. The tube configuration makes it possible to add other accuracy enhancing contraptions, for faster shooting. Since, for a reflector sight only requires a single optical surface, tube is not really essential. The other conformation is the ‘open’ design. The design consists of a flat base with a support base for the reflective optics machinery.
Most red dot sights nowadays are paired with brightness control, giving a high contrast dot in bright background. And a corresponding dim dot, so as to prevent loss of night vision in low or zero light conditions.