Relating Image Distance and Image Height

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In the discussion on the thin lens equation, participants clarify that while the distances of the object and image (s and s') cannot be directly substituted with their respective heights (h and h'), they are indeed related through the concept of transverse magnification. The transverse magnification equation, M_T = y_i/y_0 = -s_i/s_0, illustrates this relationship, as both image height and distance are derived from similar triangles in geometrical optics. The key takeaway is that while substitution is not valid in the thin lens equation, the heights and distances are interconnected through magnification principles. Understanding this relationship is crucial for accurate calculations in optics. The discussion emphasizes the importance of recognizing how these variables interact without direct substitution.
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Regarding the thin lens equation,

1/s + 1/s' = 1/f

where s= distance of object from lens, s' = distance of image from lens, and f=focal length, can h and h' (h = height of object and h' = image height) be substituted from s and s'? I know the values are related through similar triangles, I am just not positive that they can be substituted in this equation. Could anyone shed some light on this being a valid substitution?
 
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You can't replace image distances with image heights in the thin lens equation but they are related by transverse magnification.

M_T = \frac{y_i}{y_0} = -\frac{s_i}{s_0}

This occurs because in geometrical optics they both form sides of similar right triangles.
 
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