Schematic diagram illustrating gravitational lensing of a distant source. Light from a source is bent as it travels toward an observer. As a result, for a point mass lens, an observer sees two images of the source. In the sky plane (right panel), images appear distorted. If the source, the lens, and the observer are positioned in a straight line, then the source will appear as a ring around the lens in the sky plane. In the case of any misalignment, the observer will see two elongated images instead. The left and right panels show the same lensing system but seen at different viewing angles. The drawing is not to scale and is for illustrative purposes only.