Why isn flash photography permitted in museums?
Dear Straight Dope: Can you explain the rationale behind the prohibition of flash photography in many museums? Is there some dangerous “wave” or “ray” produced which could harm the painting or statue? Or . . . is this a ploy to get naive tourists to buy more post cards in the gift shop? — Mary Colpi While the markup on post cards is surely high enough to warrant some sort of clever ploy to increase sales, Mary, flash photography is prohibited for a different reason. According to Carl Grimm, head paintings conservator for the DeYoung Museum in San Francisco, the heat and light produced by flash photography speed up the chemical reactions that cause deterioration. Mr. Grimm said: In general, a 10-degree F increase in temperature doubles the speed of chemical reactions, so any increase in heat–even brief–speeds up deterioration. Heat is produced just beyond the red end of the visible light spectrum in the invisible, longer wavelengths known as infrared. The short, high-energy wavelength