Glass that is absolutely flawless, completely transparent and can be ground to shape. Glass is a fluid, not a solid.
Used for manufacturing lenses and prisms. It is specially manufactured to be free of defects and distortion, and to withstand heat and humidity. Each type f optical glass is classified according to its refractive index and light dispersive quality. Two or more types of optical glass are typically used in the component elements of photographic lenses.
clear homogeneous glass of known refractive index; used to make lenses
Glass of extreme purity and with well-defined optical properties, which was originally created for making lenses and prisms.
Glass that is used for lenses in spectacles, microscopes, binoculars, telescopes, and other objects. The glass itself must be free of impurities, since its main function is to allow as much light as possible to pass through its curved surface so that it can be refracted (bent) properly into focus.
High-quality, color-free glass having specific refractive qualities, used in lenses and other components of optical systems.
A specially manufactured glass used in the production of lenses. Ideally free of defects and distortion, and able to withstand heat and humidity.