# what is lens makers formula

The radii of curvature of the surfaces of the lens are R 1 and R 2 and their poles are P 1 and P 2.The thickness of lens is t, which is very small. The lower half of the concave mirror's reflecting surface is covered with an opaque material. Lens-Maker's Formula. The Lensmaker's formula works with this convention, although you can modify the formula and define your reference system accordingly. Firstly, lets define a reference system. A concave lens of focal length 15 cm forms an image 10 cm from the lens. Lens Maker's Formula : Using the positive optical sign convention, the lens maker's formula states where f is the focal length, n is the index of refraction, and and are the radii of curvature of the two sides of the lens. Draw the ray diagram and find the position, size and nature of the image formed. It is where the lens formula comes into the action. The radii of curvature here are measured according to the Cartesian sign convention.For a double convex lens the radius R 1 is positive since it is measured from the front surface and extends right to the center of curvature. Lens makers formula: It is a relation between the focal length of a lens to the refractive index of its material and the radii of curvature of its two surfaces. The radius R 2 is negative since it extends left from the second surface. Characteristics of images created by these lenses differ depending on the aspects of lenses and object's distance from these lenses. The lower half of the concave mirror's reflecting surface is covered with an opaque material. R1 and R2 is the radius of curvature of the lens and poles are represented by P1 and P2. (a) 0.667 (b) 1.5 (c) 0.5 (d) zero (e) data insufficient. Define lens formula. Also, put the numerical values of R 1 and R 2 equal to f]. Is lens formula applicable only for convex lens? Thickness of the lens is given by t. O is a point object which is placed on the principal axis of the lens. The manufacturers of the lenses use this relation to design the lens of a … You may substitute the same values for the focal length in air and the radii of curvature of the faces in the l ens maker’s equation and satisfy yourself that the refractive index of the lens is 1.5. [Since it is a biconvex lens, f is positive, R 1 is positive and R 2 is negative. (a) Lens Maker’s Formula: Suppose L is a thin lens.The refractive index of the material of lens is n 2 and it is placed in a medium of refractive index n 1.The optical centre of lens is C and X ' X is principal axis. As per optical physics, lens formula relates the distance of an object (u), the distance of an image (v), and the focal length (f) of the lens. The lens is placed in a medium of refractive index n1. Lets place the origin at the center of the lens and let right hand side be positive and left negative. For a thin lens, the power is approximately the sum of the surface powers.. Len’s Makers formula: Consider a thick lens L. The refractive index of the material of lens is n2. An object 5 cm high is held 25 cm away from a converging lens of focal length 20 cm. It is so called because it is used by lens manufacturers to make lenses of particular power from the glass of given refractive index. The formula giving the relation between the focal length (f) of the lens, the refractive index of the material of the lens (n) and the radii of curvature of its surface (R 1 & R 2) is known as Lens maker formula.. Derive Lens maker formula f 1 = (n − 1) (R 1 1 − R 2 1 ). Lens, Thin Lens Formula 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.