Compound microscope Definition and 6 Discussions

The optical microscope, also referred to as a light microscope, is a type of microscope that commonly uses visible light and a system of lenses to generate magnified images of small objects. Optical microscopes are the oldest design of microscope and were possibly invented in their present compound form in the 17th century. Basic optical microscopes can be very simple, although many complex designs aim to improve resolution and sample contrast.
The object is placed on a stage and may be directly viewed through one or two eyepieces on the microscope. In high-power microscopes, both eyepieces typically show the same image, but with a stereo microscope, slightly different images are used to create a 3-D effect. A camera is typically used to capture the image (micrograph).
The sample can be lit in a variety of ways. Transparent objects can be lit from below and solid objects can be lit with light coming through (bright field) or around (dark field) the objective lens. Polarised light may be used to determine crystal orientation of metallic objects. Phase-contrast imaging can be used to increase image contrast by highlighting small details of differing refractive index.
A range of objective lenses with different magnification are usually provided mounted on a turret, allowing them to be rotated into place and providing an ability to zoom-in. The maximum magnification power of optical microscopes is typically limited to around 1000x because of the limited resolving power of visible light. The magnification of a compound optical microscope is the product of the magnification of the eyepiece (say 10x) and the objective lens (say 100x), to give a total magnification of 1,000×. Modified environments such as the use of oil or ultraviolet light can increase the magnification.
Alternatives to optical microscopy which do not use visible light include scanning electron microscopy and transmission electron microscopy and scanning probe microscopy and as a result, can achieve much greater magnifications.

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  1. B

    I What is really happening in collimation of rays?

    Ok so if an object is placed at the focal point of a convex lens, it will have it's rays collimated -- which I assumed to mean that all rays would end up parallel to each other. But then, I saw this diagram of a simple compound microscope from Hecht "Optics" 5th ed: And I noticed that all...
  2. B

    I Relation between angular & lateral magnification on the retina from microscope

    Ok so for a compound microscope system like the one below, Magnification power is ## MP = M_T * M_A ##. My present understanding is that ##M_T## refers to the magnification by height ratios of the object through L1, and ##M_A##, in this case, refers to the ratio of unaided and aided angles of...
  3. Wrichik Basu

    B Which ray diagram is correct for a Compound microscope?

    Here are two ray diagrams for compound microscope, the first one proposed by the book, and the second one recommended by the teacher: In the first image, the light rays form a real image A'B', which becomes the virtual object for the eyepiece. See, the original rays are carried forward to...
  4. R

    Compound microscope

    is magnification negative for a compound microscope at infinity
  5. A

    Microscopes and telescopes

    I read that in terrestrial telescope there is an erecting lens whose function is to erect the inverted image formed by objective lens so that final image formed by eyepiece is also erect.there is no need of erecting lens in astronomical telescope because astronomical bodies are symmetrical in...
  6. M

    Compound Microscope, Ray Diagram Mistakes.

    I noticed that the ray diagram for the "how the compound microscope works" and "how the telescope works" is wrong in my government sanctioned physics textbook(and countless other books and websites!) The diagram printed was this- Name: Physics Standard XI Printed by: Maharastra State Board of...