he determined the mathematical relationship that governed the instrument's ability to magnify. A spyglass with a plano-convex lens that focuses at 12 inches and a plano-concave lens that focuses ...

Plano-concave lenses diverge a collimated beam from a virtual focus and are commonly used to balance out aberrations of other lenses in the system. MOK Optics provides plano-concave lenses fabricated ...

Meniscus lenses, which effectively combine convex and concave lenses, can be positive or negative, depending on which side of the lens is convex or concave. The meniscus lens image below shows a ...