Fresnel number

Fresnel number is a way to measure the size of something. It's like using a ruler to measure how long or short something is. To figure out the Fresnel number of something, you need to know its size and the distance it is away from you. The Fresnel Number is calculated by dividing the size of an object (in metres) by the distance away from you (in metres). Then you multiply the result with 1,000,000. The bigger the number, the bigger the object.