Lens index calculator

Calculate the refractive index of a lens based on its focal length and diameter

Input Parameters

Calculation Results

Refractive Index (n)

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Where:
n = Lens Refractive Index
f = Focal Length in mm
D = Lens Diameter in mm
The formula used is: n = f² / (D² * 0.25)

Lens index calculator Calculator Usage Guide

Learn how to use the Lens index calculator calculator and its working principles

How to use the calculator

  1. Enter the focal length (f) of your lens in millimeters
  2. Enter the diameter (D) of your lens in millimeters
  3. Click the "Calculate" button to compute the refractive index
  4. The result will be displayed in the refractive index (n) field

Working Principle

The refractive index of a lens can be calculated using the relationship between its focal length and diameter. The formula used in this calculator is:

n = f² / (D² * 0.25)

This formula assumes a simple lens geometry where the refractive index is directly proportional to the square of the focal length divided by the square of the diameter.

Applications

This calculator is useful for:

  • Optical engineers designing new lenses
  • Photographers calculating lens properties
  • Students learning optical principles
  • Researchers needing to determine material properties

Note: This calculator provides a simplified calculation for basic lens properties. For more complex lens designs, additional parameters would be needed.