Optical Lenses–Convex And Concave Lenses
Product Description
Optical thin Lens - A lens in which the thickness of the central portion is large compared to the radii of curvature of its two sides. In the early days, the camera was only equipped with a convex lens, so it was called a "single lens". With the development of science and technology, modern lenses have several convex and concave lenses with different forms and functions to form a converging lens, which is called "compound lens". The concave lens in the compound lens plays the role of correcting various aberrations.
Features
Optical glass has high transparency, purity, colorless, uniform texture, and good refractive power, so it is the main raw material for lens production. Due to the different chemical composition and refractive index, optical glass has:
● Flint glass - lead oxide is added to the glass composition to increase the refractive index .
● Crown glass-made by adding sodium oxide and calcium oxide to the glass composition to reduce its refractive index.
● Lanthanum crown glass - the discovered variety, it has the excellent characteristics of high refractive index and low dispersion rate, which provides conditions for the creation of large-caliber advanced lenses.
Principles
A glass or plastic component used in a luminaire to change the direction of light or to control light distribution.
Lenses are the most basic optical components that make up the microscope optical system. Components such as objective lenses, eyepieces, and condensers are composed of single or multiple lenses. According to their shapes, they can be divided into two categories: convex lenses (positive lenses) and concave lenses (negative lenses).
When a beam of light parallel to the principal optical axis passes through a convex lens and intersects at a point, this point is called the "focus", and the plane passing through the focus and perpendicular to the optical axis is called the "focal plane". There are two focal points, the focal point in the object space is called "object focal point", and the focal plane there is called "object focal plane"; conversely, the focal point in the image space is called "image focal point". The focal plane at is called the "image square focal plane".
