Geometrical Optics: Explaining 2 Focus Positions

Thread starter jst81161
Start date Apr 17, 2007
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Geometrical Geometrical optics Optics

AI Thread Summary

In geometrical optics, there are two focus positions for a given object screen distance due to the properties of lenses, specifically converging lenses. This phenomenon occurs because light rays can converge at two distinct points on either side of the lens, creating two possible image locations. The discussion highlights the need for clarity regarding the type of lens and the specific context of the problem. It emphasizes the importance of understanding the relevant equations and background information to fully grasp the concept. The existence of two focus positions is generally true for converging lenses under ideal conditions.

Apr 17, 2007

jst81161

Homework Statement

Explain why for a given object screen distance there are two positions where the image is in focus. Is this always true?

Homework Equations

The Attempt at a Solution

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Apr 17, 2007

berkeman

Admin

Two positions of what, the lens? What kind of lens? What is the background for this question? What are the relevant equations?

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