Sometimes Wikipedia has an entry on point:
"Visualization is a central topic in Ansel Adams' writings about photography, where he defines it as "the ability to anticipate a finished image before making the exposure". The term previsualization has been attributed to Minor White who divided visualization into previsualization, referring to visualization while studying the subject; and postvisualization, referring to remembering the visualized image at printing time. However, White himself said that he learned the idea, which he called a "psychological concept" from Ansel Adams and Edward Weston. Though the term previsualization was and continues to be used by many noteworthy photographers, and had become part of the vernacular, it is often regarded as redundant."