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Optical Instruments - Implications

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• Camera-Projector
• Magnifier
• Eyeglasses
• Compound Instruments

Optical Instruments

Object outside of the focal point.

Draw three rays that we can follow. Notice what happens when the object moves.

(click on picture)
Implications --- Example: --- Question:

Object outside of the focal point.

Draw three rays that we can follow. Notice what happens when the object moves.

(click on picture) back
Implications --- Example: --- Question:

Object outside of the focal point.

Draw three rays that we can follow. Notice what happens when the object moves.

(click on picture) back
Implications --- Example: --- Question:

Object inside of the focal point.

Follow three rays we understand as before.

(click on picture)
Implications --- Example: --- Question:

Object inside of the focal point.

Extend the final rays backward to see where they seem to be coming from --- a virtual image.

(click on picture) back
Implications --- Example: --- Question:

Object inside of the focal point.

When your eye looks at this, the virtual image occupies a larger angle than the object without the lens.

(click on picture) back
Implications --- Example: --- Question:

In the eye, a lens focuses images on the retina.
If the lens lacks converging power or the retina is too close to the lens, then rays from nearby objects are not brought to a focus.

A converging lens corrects the problem.

If the lens has too much converging power or the eyeball is too long, rays from distant objects focus before they reach the retina.

A diverging lens corrects the problem.

Implications --- Example: --- Question:

An astronomical telescope is a magnifier looking at the image formed by a camera.

A compound microscope is a magnifier looking at the image formed by a projector.

Implications --- Example: --- Question: