What Are Optical Instruments
Optical Instruments In Physics For Class 2
Optical instruments are those that enhance or clarify images for viewing and also analyze light waves to find out a number of characteristic properties. They include simple devices like periscopes, mirrors, and lenses as well as complex ones such as telescopes, microscopes, etc.
They work on the principle that converging mirrors and lenses always give bigger images while diverging ones make things smaller. You can construct a periscope, box camera, compound microscope, and telescope to learn these principles.
What is an optical instrument?
Optical instruments are devices that process light waves to enhance an image for viewing or analyze them to determine the number of characteristic properties. They can be as simple as a magnifying glass or as complicated as a telescope or microscope. They all work on the basic phenomena of reflection and refraction. Mostly, they use mirrors and lenses in different combinations for the magnification of images.
Telescopes, for example, have convex lenses to make enlarged images. This allows them to see objects that are very far away. They are used for a variety of purposes, such as astronomy and astrophysics.
Another kind of optical instrument is a microscope, which is used to study small objects such as cells and other microorganisms. They are also used in biology, chemistry, and other disciplines.
The resolving power of an optical instrument is its ability to separate two objects that are close together, such as stars in the sky. This is possible because of diffraction, which occurs when a light wave passes through a prism or other type of lens.
Other examples of optical instruments include periscopes and cameras. They use lenses and mirrors to create images of objects or scenes that cannot be seen directly. They can also be used to correct defects of vision, such as myopia (short-sightedness) and hyperopia (far-sightedness). These optical instruments can help us understand the behavior of light better.
Lenses
There are many different kinds of lenses, used in a variety of ways. They are a very important part of optical instruments such as telescopes, cameras, and microscopes. They are also used to correct vision defects such as myopia and hypermetropia.
A lens is a piece of glass or transparent plastic with two surfaces that are ground and polished to produce a convergence or divergence of light. The principal axis of a lens is perpendicular to the surface, and light rays passing through it are concentrated (or seem to diverge) at a point called the focal plane. The distance S1 to this point is called the focal length of the lens, and the distance S2 to that point is the radius of curvature of the lens.
The surface of a lens can have either a convex or a concave curvature. A lens designer must carefully control the thickness of each surface, its separation from another surface, and the distance between surfaces to make sure that the lens is designed correctly. A lens’s performance is verified by focusing light through it to form a virtual image. If that virtual image can be re-imaged with a second lens to create a real image, the performance of the lens is proven. The same principle is used to test the performance of a kaleidoscope, a simple optical instrument that consists of two or more flat mirrors tilted and joined at an angle to each other.
Telescopes
The telescope is a kind of optical instrument that allows us to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. It uses a combination of lenses and curved mirrors to magnify the image of astronomical objects. Its basic working principle is to use the principles of refraction in glass lenses. The objective lens of the telescope produces a real image of an object and the eyepiece produces a virtual image. The overall magnification is the product of the linear magnification produced by the objective lens and the angular magnification produced by the eyepiece.
Optical instruments are also used to correct defects of vision like short-sightedness (myopia) and far-sightedness (hypermetropia). These are accomplished by using spectacles with converging lenses. Another example of an optical instrument is the collimator, which has a slit at the focus of a double convex lens to get a parallel beam of light.
Some of the most important optical instruments include microscopes and telescopes, which make distant objects appear more magnified. Other optical instruments include interferometers for measuring the interference of light waves, polarimeters for measuring the dispersion and rotation of polarized light, and DNA sequencers which analyze the color and intensity of the fluorochrome attached to a specific nucleotide of a DNA strand. Other optical instruments work in other portions of the electromagnetic spectrum, such as radio telescopes and X-ray telescopes.
Cameras
Cameras capture images onto a light-sensitive surface (either film or digital sensor). These devices allow us to take snapshots of things in our environment. They are used for a wide variety of purposes, from taking pictures of people to examining the contents of microorganisms.
The most important optical component of a camera is the lens. This is a curved piece of glass or plastic that takes the rays of light bouncing off of objects and redirects them to come together as a real image. It can do this because light travels slower through different mediums, like air and the lens. The lens can also bend the rays of light, for example, by increasing its overall “bending angle.”
This is how cameras make photographs. Scientists use a device called a photodetector to convert the light from the scene into electronic signals that can be read by computers. Photodetectors are made of silicon split into millions of tiny squares (called pixels) that are sensitive to the presence of photons. When photons hit a pixel, they generate electrons in the material, which are then stored and amplified by computer software into grey levels that can be read as an image.
Cameras that are used for scientific imaging need to be quantitative, meaning they must accurately count the photons that hit the pixel and convert them into electrical signals. This requires large information storage, which is why scientists design sensors with the optimum overall size, pixel size, and number of pixels.
We believe this is helpful below is a chemistry note you can check it out.
