1. What is an eyepiece?

Eyepiece: Eyepiece is a visual optical device used to observe the image of the front optical system. It is a part of the visual optical instruments such as telescopes and microscopes. The eyepiece consists of two parts. The lens at the upper end is called the eyepiece lens, which enlarges the image. The lens at the lower end is called the convergent lens or the field lens, which makes the image brightness uniform.

2. What is an objective?

Objects: Objects are a group of lenses composed of several lenses. The purpose of combination is to overcome the imaging defects of single lens and improve the optical quality of objective lens. The magnification of a microscope depends mainly on the objective lens. The quality of the objective lens directly affects the image quality of the microscope. It is the main component that determines the resolution and image clarity of the microscope. Therefore, the correction of the objective lens is very important.

What is the difference between an eyepiece and an objective?

The objective is a threaded lens close to the object being observed. The eyepiece is threadless, close to the viewer's eye. The relationship between magnification and length of objective and objective is exactly the opposite.

Magnifier generally refers to a convex lens, while the microscope is much more complex. In principle, it can be considered that the combination of two convex lenses is that the magnified image of the first lens (objective) falls within the focal length of the second lens (eyepiece), resulting in secondary magnification.

There are two kinds of lenses on the microscopy. One is the eyepiece, which is close to the eye. The other is the objective lens, which is aimed at the observed object. Both lenses are marked with multiplied numbers. For example, the eyepiece is marked with * 10. And the objective is * 20. The actual magnification of this microscope is 10*20=200.

Generally speaking, eyeglasses are not replaced. To perform microscopic operations of different multiples, it is only necessary to change the objective lens. Generally, there are three to five objective lenses in a general microscope. Now, the most popular objective lenses are four, ten, 40, and 100 times. Another objective lens is empty. It is very convenient to use it only by turning it.