A lens can potentially create a rainbow from a broad beam of light, although traditional experiments typically use a thin beam of white light with a prism. The coherence of light is crucial for producing a spectrum, which may not be significantly affected by the beam's width. The discussion suggests that using a lens with high transverse chromatic aberration could achieve this effect, drawing on past experiences with lenses in hyperspectral imaging projects. The feasibility of this concept remains uncertain, particularly regarding the fixed distance from the lens. Overall, the exploration of lens design for rainbow creation from broad light beams presents intriguing possibilities.
