Optical black is not a colour. In fact, it is precisely the absence of colours that defines black. As a rule, there is always a bit of light left in the darkness, but for the people we meet here, the idea of perfect black is the basis of both research and fascination. The astronomer and outer space, the composer who can hear colours, and the marine biologist in the deep sea. 'Perfect Black' is a beautiful and unusual science film, which through razor-sharp black and white images and a resounding, tactile score opens up an entirely new understanding of the limits of our knowledge. A thought-provoking experience, that must be seen in the darkness of the cinema.