Main Factor Effects the Screen—Viewing Angle

Every direction of screen reflects differently, in the horizontal direction will farther away from the center of the screen, and less brightness;  when brightness drops to 50% is defined as the angle of view.

The image can be viewed within the viewing angle with satisfactory brightness.  The image is not bright enough when viewed out of perspective.Generally speaking, the larger the screen gain, the smaller the angle of view;  The smaller the gain, the larger the viewing angle.