Globalibay Fresnel Lens for Shortest DIY Projector Focal Length 185mm IndiaThe Fresnel lens reduces the amount of material required compared to a conventional lens by dividing the into a set of concentric annular sections. An ideal Fresnel would have infinitely many such sections. In each section, the overall thickness is decreased compared to an equivalent simple. This effectively divides the continuous surface of a standard into a set of surfaces of the same curvature, with step wise discontinuities between them. In some