A rectilinear lens is a type of ultrawide-angle lens designed to reproduce straight lines accurately with minimal distortion. Typically, these lenses have a focal length around 15mm or wider and are engineered to maintain linearity across the image plane.
Rectilinear lenses are especially useful in architectural, interior, and landscape photography, where preserving the geometric integrity of lines is critical. Unlike fisheye lenses, which curve straight lines at the edges, rectilinear lenses provide a natural perspective while still capturing a wide field of view, making them ideal for professional and creative applications.