Optical instrument

Optical instrument . It is used to process light waves to improve an image for display, and to analyze light waves (or photons ) to determine characteristic properties.

Summary

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  • 1 Image enhancement
  • 2 Analysis
  • 3 Others
    • 1 Photographic Camera
    • 2 Cinematographic Camera
    • 3 Galileo’s Spectacle
    • 4 Astronomical Spectacle
    • 5 Telescopes
    • 6 Optical Microscope
    • 7 Imaging
    • 8 Special Optical Microscopes
    • 9 Compound Microscope
    • 10 Periscope
  • 4 Sources

Image enhancement

The first optical instruments were telescopes used for (distant) image magnification, and microscopes used to magnify very small images. Since the days of Galileo Galilei and Van Leeuwenhoek , these instruments have been vastly improved and extended to other portions of the electromagnetic spectrum .

Analysis

Another class of optical instruments is used to analyze the properties of light or optical materials. They include:

  • Interferometer to measure the interference of light waves.
  • Photometer to measure the intensity of light.
  • Polarimeter to measure the dispersion or rotation of polarized light.
  • Reflectometer to measure the reflectivity of an object’s surface.
  • Refractometer to measure refractive index of various materials, invented by Ernst Abbe.

Others

Photographic camera

Nikon Camera (Parts)

A camera or photo camera is a device used to take pictures. It is an ancient mechanism for projecting images in which an entire room performed the same functions as a current camera inside, with the difference that at that time there was no possibility of saving the image unless it was manually traced. Today’s cameras may be sensitive to the visible spectrum or to other portions of the electromagnetic spectrum, and their primary use is to capture the field of view.

Cinematographic camera

Cinematographic Camera – Scheme

To impress the films the cinematographic camera is used that is nothing more than a photographic camera, with the difference that it has a roll of film that passes quickly between the lens, impressing from 22 to 28 photographs per second, this film is wound in the same apparatus, to be later revealed and fixed by this are perpendicular.

Galileo’s eyeglass

Galileo’s telescope or telescope

This apparatus for remote observations, it has an eyepiece consisting of a diverging lens and an objective that is a converging lens, this apparatus does not give very large magnifications, but they are practical due to their small size. It was very useful since it allowed a greater long-range view through the optical lens. The human eye is able to perceive movements in a series of images thanks to the effect of retinal persistence.

Astronomical Spectacle

This apparatus, used in the observation of celestial bodies, consists of two converging lenses: an objective and an eyepiece. The objective provides a real and inverted image and through the eyepiece the observer sees a virtual image of the same direction, that is, inverted with respect to the object. The distance between the objective and the eyepiece must be equal to the sum of their respective focal lengths.

Telescopes

Parts of a telescope

It is an apparatus which allows the human being to see through space through a series of lenses which are graduated at the distance preferred by the user to see the different spatial phenomena.

Optical microscope

Optical Microscope – Parts

The most widely used type of microscope is the light microscope, which uses visible light to create an enlarged image of the object. The simplest light microscope is the double convex lens with a short focal length. These lenses can increase an object up to 15 times. In general, compound microscopes are used, which have several lenses with which higher magnifications are achieved. Some light microscopes can magnify an object over 2,000 times.

The compound microscope consists of two lens systems, the objective and the eyepiece, mounted on opposite ends of a closed tube. The objective is made up of several lenses that create an enlarged real image of the examined object. Microscope lenses are arranged so that the objective is at the focal point of the eyepiece. When you look through the eyepiece, you see a virtual image enlarged from the real image. The total magnification of the microscope depends on the focal lengths of the two lens systems. The additional equipment of a microscope consists of a frame with a support for the examined material and a mechanism that allows the tube to be brought in and out to focus the sample. Specimens or specimens that are examined under a microscope are transparent and viewed with light passing through them;

The bracket has a hole through which the light passes. Beneath the support is a mirror that reflects light to pass through the specimen. The microscope may have an electric light source that directs light through the sample. Photomicrography, which consists of photographing objects through a microscope, uses a camera mounted above the eyepiece of the microscope.

The camera often lacks a lens, since the microscope acts as such. Photomicrography, refers to a technique of duplicating and reducing photos and documents to a minuscule size to save them in a file. Microscopes used in scientific settings have several enhancements that allow a comprehensive study of the specimen. Since the sample image is magnified many times and inverted, it is difficult to move it manually. Therefore, the supports of high-powered scientific microscopes are mounted on a platform that can be moved with micrometer screws.

Some microscopes have rotating stands. All research microscopes have three or more objectives mounted on a moving head that allows the magnification power to be varied.

Imaging

The most widely used type of microscope is the light microscope, which uses visible light to create an enlarged image of the object. The simplest light microscope is the double convex lens with a short focal length. These lenses can increase an object up to 15 times. In general compound microscopes are used, which have several lenses with which greater auents are achieved. Some light microscopes can magnify an object over 2,000 times.

The compound microscope consists of two lens systems, the objective and the eyepiece, mounted on opposite ends of a closed tube. The objective is made up of several lenses that create an enlarged real image of the examined object. Microscope lenses are arranged so that the objective is at the focal point of the eyepiece. When you look through the eyepiece, you see a virtual image enlarged from the real image. The total magnification of the microscope depends on the focal lengths of the two lens systems.

Special Optical Microscopes

There are various light microscopes for special functions. One of them is the stereoscopic microscope, which is nothing more than a pair of low power microscopes positioned so that they converge on the specimen. These instruments produce a three-dimensional image. The ultraviolet light microscope uses the color range of the light spectrum instead of the visible range, either to increase resolution with a shorter wavelength or to improve the quality of detail by selectively taking different lengths of the ultraviolet and ultra-red band .

Compound microscope

Compound Optical Microscope – Parts

It is the commonly known microscope and is fundamentally made up of two lenses: the eyepiece and the objective. The objective: It has a small focal length and is placed near the object to be observed. The eyepiece: It has a greater focal length than the previous one and it is the one closest to the observer’s eye. Both lenses are located in a tube and in such a way that their axes coincide. This tube can be raised or lowered by means of a micrometer screw to achieve the necessary focus on the object. Then the image obtained will be real, inverted and larger.

Periscope

Periscope in submarines

A simple periscope consists of mirrors or prisms located at opposite ends of a tube with the reflection surfaces parallel to each other on the axis of the tube. The so-called field or tank periscope has been used in trenches, behind parapets and embankments, and in tanks , allowing you to see safely.

Outline of a periscope

The submarine’s periscope is a larger and more complex instrument, made up of reflection prisms at the top of the vertical tube, with two telescopes and several lenses between them and an eyepiece at the bottom. This periscope is placed in a thick, sturdy tube, 10 to 15 cm in diameter, that withstands the pressure of water at great depths. The only rotating part of the outer tube is the head, attached to the inside of the tube. This can be rotated by a lever or a shaft and a gear.

The field of view of a simple periscope is small, but some recent improvements have increased it. The magnification of distant objects is 1.5 to 6 diameters. Periscopes are also used as sighting devices in military aviation

 

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