Photos required a very long exposure back then and a smile is hard to keep for what amounted to minutes. Keeping a neutral expression minimized movement and con

Photos required a very long exposure back then and a smile is hard to keep for what amounted to minutes. Keeping a neutral expression minimized movement and consequently blur resulting in an expensive re-shoot. http://www.csmonitor.com/Innovation/Horizons/2011/1118/Louis-Daguerre-Why-people-never-smile-in-old-photographs http://www.csmonitor.com/Innovation/Horizons/2011/1118/Louis...