mezzotint vs photograph

mezzotint

noun
  • A form of intaglio etching in which a metal plate is roughened evenly and then smoothed to bring out an image. 

  • An etching or print made using this method. 

verb
  • To make such etchings 

photograph

noun
  • A picture created by projecting an image onto a photosensitive surface such as a chemically treated plate or film, CCD receptor, etc. 

verb
  • To appear in a photograph. 

  • To fix permanently in the memory etc. 

  • To take a photograph (of). 

How often have the words mezzotint and photograph occurred in a corpus of books? (source: Google Ngram Viewer )