The earliest microscopes could only magnify an object 10 times its actual size and were called "flea glasses."
Compound microscopes include at least two lenses, the objective and the eyepiece, and create an enlarged image of a specimen on the slide. The magnification of a microscope is the ratio of the angle the object subtends to the angle subtended by the object as seen through the microscope. Calculating the total magnification of your microscope is extremely simple and straightforward. Depending on what kind of information you have to start with, there are two ways to do it.
Instructions
1. Look at the objective lens on your microscope and the eyepiece lens. Each lens should be labeled with the magnification power of the lens: 10x, 20x, etc. If you're working a practice problem on a physics quiz that doesn't give you this information, skip this and the following step and proceed to Step 3.
2. Multiply the magnification power of the objective by the magnification of the eyepiece to determine total magnification. If the eyepiece is 10x, for example, and the objective is 4x, total magnification is 40x.
3. Use the following equation to find magnification if you're working a problem on a physics quiz: M = -L / f1 (25 cm / f2), where M is magnification, f1 is the focal length of the objective, f2 is the focal length of the eyepiece and L is the lens spacing. The above is based on the equation for total magnification, magnification of objective x magnification of eyepiece, and the equation for single lens magnification.
Tags: total magnification, magnification eyepiece, eyepiece lens, focal length, magnification power, objective magnification