👉 Semilens, also known as a spherical lens, is a type of optical device that consists of two lenses placed side by side. The focal length of a semilens is defined as its distance between the two lenses. It can be used to create an image on the screen when viewed from an angle different than 90 degrees. Semilenses are useful in various applications, such as photography and video recording. They are particularly useful for capturing small or distant objects without distortion or loss of
