Ash: Import converted Year 1 Semester 1 lecture notes from 443937a7d37850a3c57dfa863f35e80d07f2ccbc

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Import converted Year 1 Semester 1 lecture notes from 443937a7d37850a3c57dfa863f35e80d07f2ccbc

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<b>Lecture 13: Image Formation</b><br>
Wed 12 Nov 2025 11:00
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[[Year 1 Sem 1/LC Optics and Waves/Lecture 12|← Previous lecture]] · [[Year 1 Sem 1/LC Optics and Waves|Module]]

== Sign Rules ==

We have the mirror equation: <div class="pn-import-equation"><nowiki>$$\frac{1}{s} + \frac{1}{s^\prime} = \frac{1}{f}$$</nowiki></div>

The numerical values of <nowiki>$s$</nowiki> and <nowiki>$s^\prime$</nowiki> give us the distance, but the position of the formed image is determined by their signs.

== Mirrors ==

The image formed by a mirror is:

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<i>Virtual</i>, as we effectively see it appears as being behind the mirror, where there is no real light.

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<i>Erect</i>, as there is no inversion (if you stand in front of a mirror, you see your body in the same top-to-bottom orientation as real life).

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<i>Reversed</i>, as if you look in a mirror your body faces you, and you see your face, not your back.

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=== Angled Mirrors ===

If we have a pair of hinged mirrors, changing the angle between them changes the way that the image is produced. Crucially, it changes how many images of the object we see:

[[File:OW-Y1S1-lec13-01.png|thumb|center|600px]]

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[[Year 1 Sem 1/LC Optics and Waves/Lecture 12|← Previous lecture]] · [[Year 1 Sem 1/LC Optics and Waves|Module]]

Year 1 Sem 1/LC Optics and Waves/Lecture 13 - Revision history

Ash: Import converted Year 1 Semester 1 lecture notes from 443937a7d37850a3c57dfa863f35e80d07f2ccbc