Telescopic , often called scopes, Open S ights , Reflective , red dot type, and Laser Sights . Telescopic sights are best at long ranges in bright light. Open sights are good at medium ranges in all light levels. Well, except night. Reflective sights are good from medium to short ranges and are useful in any light condition.
Laser sights are useful only at short ranges and in low light levels.
The Telescopic Sight. Telescopic sights were designed to hit targets at long ranges. They use magnifying glasses to work like a telescope to zoom in on a target to place a shot just where you want it. Laws of physics being what they are, if you magnify an image, it will not be as bright unless the lenses gather up more light than the eye needs to see. The smaller the lenses, the darker the images will be.