Question

find the position of the aplanatic point of a curved refracting surface... ​

Answer 1

Answer:

When a narrow beam of light is obliquely incident on a refracting surface, astigmatism is introduced, and the image of a point source formed by a small lens aperture becomes a pair of focal lines, a series of beam sections being indicated in Figure 11.1. One focal line (sagittal) is radial to the field and points toward the lens axis, while the other focal line (tangential) is tangential to the field.

Explanation:

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