Simple microscope
Intermediate
Magnifying glass angular magnification.
M = 1 + D/fA convex lens used as a magnifier with the object inside the focal length. Maximum angular magnification M = 1 + D/f, with D = 25 cm.
f = 5 cm: M = 6.
Image is virtual.
In more detail
A simple microscope is a converging lens used as a magnifying glass. Viewing an object at the focal length gives a magnified virtual image that appears at comfortable distance.
Real-world uses
- Jewellers and watchmakers use simple microscopes to inspect details.
- Hand lenses are used for close inspection in biology.
- Jewellers and watchmakers use a simple magnifying glass to see small details clearly.
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Frequently asked questions
How is magnification found?
For an image at the near point, M = 1 + D/f, where D is the near point distance.
Why use a converging lens?
It produces a magnified virtual image that the eye can view.
How much does a magnifying glass magnify?
It depends on the focal length and how close you hold it, with the magnification being roughly the near point distance divided by the focal length, plus one.
Related topics in Optics
Lens aberrations · Human eye · Defects of vision · Compound microscope · Astronomical telescope · Reflecting telescope