Microscope and Telescope

Optical instrument

The instruments, which are used to produce an image of an object by using a lens or a combination of lenses, are called optical instruments. Examples are a Photographic camera, microscope, telescope, etc.

Photographic camera

A photographic camera is an optical instrument that is used to record a permanent image of an object on a photographic film.

The construction of camera is based on the principle thatwhen an object is placed beyond 2F of a convex lens. A real, inverted and diminished image is formed between F and 2F on the other side of the lens.

Microscope:

A microscope is an optical instrument that is used to see the details of very small objects which cannot be seen through our naked eyes.

A microscope forms highly magnified images of the tiny objects by a system of combined lenses due to which it becomes possible to see the details of very tiny objects through a microscope.

Telescope

A telescope is an optical instrument that is used to see the details of the distant objects.

Construction:

An astronomical telescope two convex lenses are used ( one objective and other eye-piece) are fitted at the outer ends of two metal tubes which can slide into one another. The objective of an astronomical telescope has a large focal length but the eye-piece has a short focal length.

In order to bring the telescope in normal adjustment, the telescope is focused at infinity that can be achieved by turning the adjustment knobs, In the normal adjustment, a person can view distant objects clearly.