1. An imaging device, comprising: a main photography unit that photographs a photographic subject and acquires a photographic image; a preparatory image acquisition unit that performs preparatory photography before and/or after the main photography unit acquires the photographic image, and acquires preparatory images; a photographic information acquisition unit that acquires photographic information related to a circumstance of photography when the preparatory images are acquired by the preparatory image acquisition unit; and a recording unit that records the photographic information and the photographic image upon a recording medium in mutual correlation.