Optical instruments are any equipment that uses a single or several lenses to take in light as an input and perform any action on it, depending on the equipment’s purpose, to either enhance an image for clearer viewing or enlarge it. Optical instruments have been developed and used for ages. In this article, we will explore the functions of different optical instruments.
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What are Optical Instruments?
Optical instruments are devices which use light rays for one of two purposes.
- Enhancement of images for viewing
- Analysis of light to determine different characteristic properties
We can define an optical instrument as:
A device that either process light waves to enhance an image for viewing, or analyzes light waves to determine one of a number of characteristic properties.
Enhancement of Images
The most common types of optical instruments in this category are microscopes and astronomical telescopes. Astronomical telescopes are used to magnify distant objects in order to see them clearly.
There are three types of Astronomical telescopes:
- Refracting telescopes: These use a combination of lenses to form a magnified image.
- Reflecting telescopes: These instruments use a combination of mirrors to form a magnified image.
- Catadioptric telescopes: These instruments use a combination of both lenses and mirrors to form images.
Other than these three main types of optical telescopes, there are many others classified according to their varying tasks.
Microscopes
Microscopes are instruments designed to magnify small objects. A simple microscope uses only one lens for the sake of magnification whereas a compound microscope uses more than one lens. A compound microscope uses two lenses, one as the objective and the other as the eyepiece.
Camera
Camera is another type of optical instrument. The objective is a converging lens. Light from a distant object is refracted through the objective lens and when the film is “exposed” to the light for a short span, the image is etched onto it. A digital camera does not use films, however. The image, in this case, is captured by image sensors and reproduced in the many numbers of ways available.
Slide and film projectors
These are other examples of optical instruments. The image is illuminated and by using a combination of lenses magnified and projected onto a screen where it is displayed. Simple tools like magnifying lenses are also optical instruments.
Analysis of Light
Instruments like photometers (used to measure light intensity), polarimeters (used to measure the rotation of polarized light), and others are used to measure different characteristics of light waves.
For example, a refractometer is used to measure the refractive index of various materials when light passes through them.
Learn about different types of optical instruments and their working principles with the help of our expert tutors here at BYJU’S.
Frequently Asked Questions – FAQs
What are optical instruments?
What are the types of astronomical telescopes?
Types of Astronomical telescopes are:
Are the magnifying lenses considered optical instruments?
Which optical instrument is used to measure the rotation of polarized light?
What is a refractometer?
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