Optical instruments use mirrors and lenses to reflect and refract light and form images. The knowledge of light was needed for the invention of optical Instruments. Optical instruments process light wave to enhance an image for a more clearer view. In addition to magnifying the distant or tiny images, these devices are used to analyze the properties of optical materials and light. Remember that you use converging lenses to make things appear larger and on the other hand, diverging lenses always get you smaller images.
When using a converging lens, it's helpful to note these rules of thumb. If the object is very far away, the image will be tiny and very close to the focal point. As the object moves towards the lens, the image moves out from the focal point, growing as it does so. The object and image are exactly the same size when the object is at 2F, twice the focal distance from the lens. Moving the object from 2F towards F, the image keeps moving out away from the lens, and growing, until it goes to infinity when the object is at F, the focal point. Moving the object still closer to the lens, the image steadily comes in towards the lens from minus infinity, and gets smaller the closer the object is to the lens.
With a diverging lens, it always produces a virtual image. The image are located on the same side of the lens where the objects lie, virtual, upright and reduced in size i.e. smaller than the specified object. The location of the object does not affect the image, hence the characteristics of the images formed by diverging lenses are easily predictable.
The first optical instruments were microscopes used for magnifying very tiny images and telescopes used for magnification of distant images. Since the days of Galileo and Van Leeuwenhoek, these instruments have been greatly improved. Today, we now have a wide range of optical instruments available for everyone to use thanks to the help of the scientist and inventors. Optical instruments such as Microscopes , telescopes, cameras and many others play a vital role in our lives.
Microscopes like no other single invention has revealed secrets of the natural world and enabled scientists to see entire new worlds, led to many discoveries in medicine and biology. Some examples include the discovery of cells, identification of bacteria and single-celled organisms. With the development of more powerful microscopes, viruses were discovered and even atoms finally became visible. These discoveries changed our ideas about the human body and nature of life.
Telescopes like microscopes use convex lenses to make enlarged images. It makes distant objects appear magnified. There are two basic types of telescopes: reflecting telescopes and refracting telescopes. A reflecting telescope uses a concave mirror to collect and focus light. A refracting telescope uses a convex mirror to collect and focus light. They differ in how they collect light, but both use convex lenses to form enlarged images.
Cameras are optical instruments that forms and records images of an object. The image may be recorded on film or it may be detected by an electronic sensor that stores the image either on a photo paper or digitally. Regardless of how the image is recorded, all cameras form images in the same basic way.
Optical instruments have a endless variety of uses. The possibilities are enormous and are very important devices.