Encircled energy refers to the amount of energy contained within a specific area around the center of an aperture. It is often used to measure the quality of an optical system, such as a telescope or camera lens.
Encircled energy is typically measured by taking a series of images of a point source of light, such as a star, at different distances from the center of the aperture. The amount of light within a certain radius around the center is then calculated and compared to the total amount of light captured by the aperture.
The shape of the aperture can affect the distribution of light and therefore the encircled energy. A circular aperture, for example, will have a more uniform distribution of light compared to a triangular or square aperture, which may have more concentrated areas of light.
The encircled energy for different aperture shapes can provide valuable information about the quality and performance of an optical system. A higher encircled energy indicates a more efficient system with better image quality, while a lower encircled energy may indicate aberrations or imperfections in the system.
Optimizing encircled energy for different aperture shapes involves finding the right balance between the amount of light captured and the distribution of that light. This can be achieved through careful design and testing of the optical system, including the shape and size of the aperture, as well as the placement and quality of any lenses or mirrors within the system.