Design Theory  - Most of the design theory incorporated in Gunstar Reticles evolved from military weapons design and experienced pro competitors. These designs take advantage of the eye's natural ability and human instinct. One of the most common examples is Natural Centering. You will instinctively center and object inside of another object so as to provide and even border. Example: Make an "O" with your fore finger and thumb, now pick an object or other point of interest that will fit inside of the "O", hold your finger "O" at arms length and look at the point of interest through the "O". Where is it --dead center of the "O"-- without even thinking about it. Gunstar Sighting Solutions uses four primary natural aiming techniques in it's designs most in combination with another. These are described in the next paragraph. Design Codes - ET,Edge Tracking - The eyes most accurate aiming ability is it's capability to edge track, or keeping one line next to another. Such as tracking the back of the foreleg on a 3D target or the back of a silhouetted target with a horizontal line.