Telescope
A telescope is an optical instrument using lenses, curved mirrors or a combination of both to observe distant objects or various devices used to observe distant objects by their emission, absorption or reflection of electromagnetic radiation.
A telescope objective is designed to capture light from something far away, so the light arriving is nearly parallel, and focus it to a real image that can be further magnified by the eyepiece. The objective also needs to be relatively large, large enough to capture enough light to make the object being viewed bright enough to resolve details. The focal length of the objective tends to be large, from about 0.5 m up to several meters, since magnification is proportional to objective focal length. The optical system is often folded to keep the mechanical tube compact.
What You Need To Know About Telescope
- Telescope is used for observing distant images of heavenly bodies such as stars and planets.
- The objective lens has a large focal length and large aperture.
- The eye lens used has small focal length and small aperture.
- The distance between the objective lens and eye lens is adjusted to focus the object situated at infinity.
- Telescopes lack an illumination system, they show objects by the light emitted by or reflected from the objects.
- Telescope eyepieces are usually marked with their focal length.
- The eyepiece produces a virtual image that is at or near infinity. The ratio between objective and eyepiece focal lengths gives the angular magnification of the telescope.
- Types of telescopes include: X-ray telescopes, Optical telescope, Infrared telescope, Sub-millimeter telescope and radio telescope.
Microscope
A microscope is an instrument that magnifies objects otherwise too small to be seen, producing enlarged images of small objects, otherwise too small to be seen by naked eyes, hence allowing the observer an exceedingly close view of minute structures at a scale convenient for examination and analysis.
A microscope has an objective with a small focal length. The objective is physically small (though it can have a large numerical aperture because of the short focal length). The objective forms a real image of the subject within the microscope tube; the magnification of this images ranges from about 4 to 100 with respect to the original subject. Then an eyepiece magnifies this real image further. The overall magnification is the product of the objective magnification and the eyepiece magnification.
What You Need To Know About Telescope
- Microscope is used for observing and magnifying images of tiny objects.
- The objective lens has a small focal length and short aperture.
- The eye lens used has moderate focal length and large aperture.
- The objective and eye lens are kept at a fixed distant apart, whereas the distance of the objective lens from the object is adjusted to focus an object.
- In a microscope, there can be as many lens elements (and more adjustments) in the illumination system than in the imaging system.
- Microscope eyepieces are usually marked with the magnification when used as a magnifier.
- Eyepiece magnifies real image. The overall magnification is the product of the objective magnification and the eyepiece magnification.
- Types of microscope include: Compound microscope and Stereo microscope.
Also Read: Difference Between Light Microscope And Electron Microscope
Difference Between Telescope And Microscope In Tabular Form
BASIS OF COMPARISON | TELESCOPE | MICROSCOPE |
Use | Telescope is used for observing distant images of heavenly bodies such as stars and planets. | Microscope is used for observing and magnifying images of tiny objects. |
Objective Lens | The objective lens has a large focal length and large aperture. | The objective lens has a small focal length and short aperture. |
Focal Length | The eye lens used has small focal length and small aperture. | The eye lens used has moderate focal length and large aperture. |
Distance Between The Objective Lens And Eye Lens | The distance between the objective lens and eye lens is adjusted to focus the object situated at infinity. | The objective and eye lens are kept at a fixed distant apart, whereas the distance of the objective lens from the object is adjusted to focus an object. |
Illumination | Telescopes lack an illumination system, they show objects by the light emitted by or reflected from the objects. | In a microscope, there can be as many lens elements (and more adjustments) in the illumination system than in the imaging system. |
Marking | Telescope eyepieces are usually marked with their focal length. | Microscope eyepieces are usually marked with the magnification when used as a magnifier. |
Image | The eyepiece produces a virtual image that is at or near infinity. The ratio between objective and eyepiece focal lengths gives the angular magnification of the telescope. | Eyepiece magnifies real image. The overall magnification is the product of the objective magnification and the eyepiece magnification. |
Also Read: Difference Between Real And Virtual Image