What is crown optics?

Crown optics is a type of optical glass that has a low refractive index and low dispersion, making it ideal for lenses that need to reduce chromatic aberration. It is made from a combination of various elements such as silicon, sodium, and potassium, and has a relatively high density compared to other types of optical glass. Crown optics is commonly used in camera lenses, telescopes, and microscopes to produce high-quality images with minimal distortions or aberrations. Some of the popular brands that use crown optics in their products include Zeiss, Nikon, and Leica.