Comparing equation (4) and (5) We get 1/v ? Lensmaker's Equation formula: 1/f = (n l /n m - 1) * ( 1/r 1 - 1/r 2) where: f: Focal Length, in meter n l: Refractive Index of Lens Material, in meter n m: Refractive Index of Ambient Medium, in meter r 1: Curvature Radius of the First Surface, in meter r 2: Curvature Radius of the Second Surface, in meter This equation holds for all types of thin lenses. Let us consider an object OO ′ placed on the principal axis with its height perpendicular to the principal axis as shown … The refractive power (inverse of focal length) can be computed from this formula. Magnification. If the surface is facing away from the object, then we simply use the opposite sign of if the surface faced the object. It is used for determining the focal length of a thin lens (thickness = 0) with radii of curvature r1 and r2. The lens maker’s equation is another formula used for lenses that give us a relationship between the focal length, refractive index, and radii of curvature of the two spheres used in lenses. (7) which is known as the lens formula. Using the formula for refraction at a single spherical surface we can say that, For the first surface, For the second surface, Now adding equation (1) and (2), When u = ∞ and v = f. But also, Therefore, we can say that, Where μ is the refractive index of the material. If the lens is in a medium of index n = A radius of curvature is positive when its center of curvature … The Lens Maker’s Equation for Thin Lenses: \frac 1f ~= ~ (n-1) \left (\frac {1} {R_1}~-~ \frac {1} {R_2} \right) The radius of curvature can be positive or negative, depending on which way it curves and where it's facing 2. 1/u = 1/f ??.. This is the lens maker formula derivation. Lensmaker Equation is used to determine whether a lens will behave as a converging or diverging lens based on the curvature of its faces and the relative indices of the lens material and the surrounding medium. This formula is true for concave lens also. Lens manufacturers use this relation to construct a lens of a particular power. Lensmakers equation: 1/f = (n 1 /n m-1) * (1/r 1-1/r 2) Where, n 1-Refractive Index of Lens Material n m-Refractive Index of Ambient Medium r 1-Radius of Curvature of the First Surface r 2 - Radius of Curvature of the Second Surface Related Calculator: If the lens is in another medium, such as water, its lens strength will be diminished. When a convex surface faces the object, we say its radius of curvature is positive. This is called the lens maker?s formula, because it tells what curvature will be needed to make a lens of desired focal length. the thin lens approximation of the power is P = diopters which corresponds to focal length f = cm. Thin Lens Equations & Calculators The position, orientation, and size of an image formed by a lens are determined by two things: the focal length of the lens and the position of the original object. 2. When a concave surface faces the object, we say its radius is negative. The lens maker formula is a relation between the focal length, the refractive index of constituent material, and the radii of curvature of the spherical surfaces of a lens.