Simple lens Simple lens In optics, a simple lens or singlet lens is a lens consisting of a single simple element. Typical examples include a magnifying glass or a lens in a pair of simple reading glasses. Simple lenses are prone to aberrations, especially chromatic aberration. They cannot be used for precise imaging and make poor camera lenses. They are commonly used for laser applications, however, where the beams are both monochromatic (minimizing chromatic aberration) and narrow (minimizing spherical aberration). Some cameras with fixed lenses have been made using a simple lens, usually a meniscus lens with the convex face facing outward.
Refracting telescope principles. The combination of an objective lens 1 and some type of eyepiece 2 is used to gather more light than the human eye is able to collect on its own, focus it 5, and present the viewer with a brighter, clearer, and magnified virtual image 6. The objective in a refracting telescope refracts or bends light. This refraction causes parallel light rays to converge at a focal point; while those not parallel converge upon a focal plane. The telescope converts a bundle of parallel rays to make an angle α, with the optical axis to a second parallel bundle