Dictionary > Numerical aperture

Numerical aperture

numerical aperture
For a lens the resolving power depends upon the wavelength of light being used and inversely upon the numerical aperture. The N.A. Is the product of the refractive index of the medium (1 for air, 1.5 for immersion oil) and the sine of the angle, i, the semi angle of the cone formed by joining objects to the perimeter of the lens. The larger the value of N.A., the better the resolving power of the lens, most objectives have their N.A. Value engraved on the barrel and this should be quoted when describing an optical system.


You will also like...

Young plant growing from the soil.
Soils

Nutrients in the soil are essential to the proper growth of a land plant. This tutorial deals with the properties of soi..

Developmental Biology
Developmental Biology

Developmental biology is a biological science that is primarily concerned with how a living thing grows and attains matu..

mRNA
Protein Synthesis

Part of the genetic information is devoted to the synthesis of proteins. mRNA, a type of RNA, is produced as a transcri..

Disturbance on a still water
Abiotic Factors – Water Conditions

A still body of water may be disturbed by a variety of factors. One of them is wind. In fact, it is considered as the pr..

Genetics – Lesson Outline & Worksheets
Genetics – Lesson Outline & Worksheets

  Topics Modules Quizzes/Worksheets Description Introduction to Genetics Genetics – Definition: Heredity and ..

Genetics and Evolution
Genetics and Evolution

Humans are diploid creatures. This means that for every chromosome in the body, there is another one to match it. Howeve..