Indicates the viewing range to be photographed. To calculate this angle, take a diagonal line out from the front of the lens to show the extreme visible edge, and another line directly out, in line with the lens. This angle will change, depending on the focal length of the lens.

For light control film, the full angle through which the film will transmit light. This value is centered about the louver angle of the film.

The viewing angle of a device or piece of hardware is the maximum angle where users can still view the display well. Different types of devices and displays have different viewing angles, due to thing [..]