In many pictorial art museums we find a prohibited sign to take flash photographs. Is it an exaggerated measure? Is it a way to avoid disturbing others? Are we affecting the paintings if we immortalize them with the flash of our camera?
Well, the measure is not as capricious as it seemed. Formerly, the paintings were painted with chemical compounds, mostly organic, that they are able to absorb light radiation. Simply shooting your camera will not cause visible damage. But imagine the millions of annual visitors a museum has, and how many shots each can take.
Therefore, each specific material (cloth, paper, painting on board, oil, mural ...) has its parameters that are measured with the lux meter, an instrument used to measure the over exposure of materials. As he explains Javier Martín in his book 365 amazing curiosities of science, history and religions:
This uptake can activate photochemical reactions that denature and alter the original pigments. It is now known that the irreversible damage detected in works exhibited in some museums was caused by the old discharge lamps that emitted ultraviolet and violet radiation. The same detrimental effect of current flashes.
However, despite existing studies, such as Poly (vinyl acetate) paints in works of art: A photochemical approach or Pursuing the fugitive: Direct measurement of light sensitivity with micro-fading tests, there are also some skeptics that the flash has such an important effect on the paintings. And that this position so jealous about the photos with flash (and in some places even without flash) It is due to commercial issues: maybe so that you buy more souvenirs in the museum shop, maybe there are conflicts with intellectual property, maybe so you can't show the inside of the place to other people so that they must go personally to see it. Be that as it may, better safe than sorry?
Image | Pablo Ibañez