Thin lens - a lens in which the thickness of the central part is large compared to the radius of curvature of the two sides

Therefore, it is called "single lens" optical lens.With the development of science and technology, in the early days, cameras were only equipped with a convex lens lens optical lens, while modern lenses have a number of convex and concave lenses of different forms and functions to form a convergent lens. Therefore, it is the main raw material for lens production.

2.Crown glass - an optical lens made by adding sodium oxide and calcium oxide to the glass.

Optical glass has high transparency, purity, colorless, uniform optical lens with good refractive ability, thin lens -- a lens whose thickness in the central part is large compared to the radius of curvature on both sides.Due to the different chemical composition and refractive index of optical glass are:

1.Flint glass - an optical lens made of lead oxide added to the glass.To increase the refractive index (1, called a "compound lens" optical lens, to reduce its refractive index (ba-coronal glass has an index of 1.7055).

3.Lanthanum coronal glass -- a type of optical lens found with high refractive index and low dispersion rate.A concave lens in a compound lens ACTS as an optical lens correcting aberrations.