Links and references from this episode:

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• Camera obscura
  
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  • Wikipedia: Camera obscura
    
  • Encyclopædia Britannica: Photography
    
  
  
  
• Nicéphore Niépce
  
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  • Maison Nicéphor Niépce: The History of Photography
    
  
  
  
• Louis-Jacques-Mandé Daguerre
  
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  • Mental Floss: Daguerreotype Q&A
    
  
  
  
• Henry Fox Talbot
  
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  • Wikipedia: Calotype
    
  
  
  
• Later photography
  
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  • Wikipedia: Collodion process
    
  
  
  
• Smiling in early photographs
  
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  • IEEE Transactions on Computational Imaging: A Century of Portraits: A Visual Historical Record of American High School Yearbooks
    
  • Library of Congress: Her Majesty’s gracious smile. An instantaneous photograph from life
    
  • Critical Studies in Media Communication: Why We Say “Cheese”: Producing the Smile in Snapshot Photography