Principle analysis of non spherical lens for spherical turntable

The commonly used ordinary camera lens is a spherical lens, which uses spherical lenses instead of flat ones. Generally, spherical lenses may exhibit aberrations such as spherical aberration, chromatic aberration, coma, etc. Therefore, actual camera lenses usually require multiple lenses with different degrees of concavity and convexity to be grouped and combined for correction. Simple fixed focus lenses generally require 4 lenses in 3 groups, 6 lenses in 4 groups, or 7 lenses in 4 groups, while high-end zoom lenses require a combination of more than 10 lenses in 10 groups. Obviously, this not only increases the volume and weight of the lens, but also reduces the amount of transmitted light. For high-sensitivity lenses with low F-values, the larger the effective aperture, the greater the spherical aberration, and of course, the more difficult it is to correct. It is precisely due to the shortcomings of spherical lenses that non spherical lenses have been developed.

The lenses used in aspherical lenses are non spherical lenses, and their surface shape is also finely adjusted based on the spherical surface shape. From a mathematical perspective, the surface shape of a sphere is a quadratic function, while the surface shape function of a non sphere is a fourth-order or even higher-order function, making the surface shape of a non sphere more complex. In fact, it is a complex non spherical surface obtained by artificially controlling the pre designed subtle surface undulations on the basis of a spherical surface.

Due to the lens shape of the non spherical lens, it is precisely designed and calculated by precision instrument optical grinding, taking into account the various correction factors mentioned above. Therefore, a single non spherical lens can achieve the effect of correcting aberrations for multiple spherical lenses. In this way, non spherical lenses can effectively reduce the number of lenses, thereby reducing the volume and weight of the lens, improving transparency, accurately restoring color difference, and improving imaging quality.