Increasing Contrast using Optical Methods

Many microscopic specimens are either very thin or transparent or lack color. They lack contrast and can not be easily seen in bright microscope light. In many cases it is not possible or desirable to chemically stain the specimens. In this case, optical techniques become necessary to enhance contrast.

Types of Objectives

Sunflower stem, cross section.

This article gives you an overview of different types of microscope objectives, but I must note that a particular objective can fall into several categories at the same time. For educational work, parfocal, achromatic, bright field objectives are very common.

Lens Errors

Maize. Vascular tissue.

Modern microscope optics correct a range of different lens errors or aberrations. Here is a short description of some common lens errors.