Sir Isaac Newton

Sir Isaac Newton in 1666 was the first to realise that white light was a combination of all of the colours of the rainbow. His experiments with prisms led the way for other scientists to probe the secrets of the spectrum. Until Newton, prisms were regarded as little more than playthings. Newton used them to break sunlight up into its constituent colours. It's not obvious that white results from combining colours. If you take red, orange, yellow, and all the other rainbow colours of paint and mix them up, you just get a murky brown-black. But if you do the same by mixing light from red, blue and green filters, the result is white.

Reflecting prisms may invert, rotate, deviate or displace a beam. Dispersing prisms produce spectral separation for spectroscopic applications or tuning a laser output.

There are many types of prism, each having a particular geometry, used to achieve the reflections required to perform a specific imaging task.

'A Rainbow is nature's Prism on a grand scale'