Which optical effect was exploited in Alhazen's Camera Obscura to observe solar eclipses safely?

💡 Explanation

When light passes through a small hole, pinhole projection occurs because light rays from different parts of the scene converge and invert on the opposite surface, creating a focused image without lenses. Therefore, pinhole projection resulted facilitating eclipse observation, rather than diffraction, refraction, or polarization which involve different optical elements.

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