What is the ultra-low dispersion lens of lens?

ED (ultra-low dispersion) ultra-low dispersion lens: effectively solve the dispersion problem of general lenses. Although the spherical aberration of general optical lenses is low, relatively speaking, they will also produce large light scattering, that is, chromatic aberration, mainly because different colors of visible light (red, blue, green ...) have different wavelengths. The refractive index passing through the optical lens is also different, so it can't converge on the same plane. Especially on the telescope head with long focal length, the red and blue with short wavelength are easy to cause obvious dispersion, and the image clarity and color sharpness are greatly affected.

ED (ultra-low dispersion) lens is an innovative lens of Nikon, which is used to solve the problem that other types of high-performance lenses (such as calcium fluoride compound lens) are fragile and easy to scratch. ED lens can reduce chromatic aberration and ensure that all wavelengths of light really focus on the same point. Therefore, an image with strong contrast between light and dark but almost no color distortion will be produced.

ED lens is the name given by the lens made of special glass, which has the characteristics of reducing telephoto chromatic aberration and astigmatism wavelength. Generally, the most ideal material for ultra-low dispersion lenses is a mineral called fluorite. However, fluorite is scarce and difficult to process. Therefore, at present, ED lenses are all artificial fluorite imitating the optical characteristics of fluorite, and generally about 1-4 pieces are inserted into telephoto lenses. Nikon is unique in the field of optical lens technology. As early as 1970s, it released the first ed ultra-low dispersion optical lens, which effectively solved the dispersion problem caused by the general telephoto lens and made your photography colorful, sharp and rigid. Therefore, especially for digital cameras, ED lens is recommended.