In the digital age, there has been a phenomenal rise in the number of photos people capture, share, and manipulate—a trend that shows no sign of slowing. Furthermore, research shows that photos—authentic and manipulated—are powerful; they can change people’s memories for distant and recent experiences, beliefs about past actions, intentions for future actions, and judgements. Yet there is currently limited research exploring the effects of digital photography on memory, cognition, and behaviour. Part One of this thesis comprises of a program of research that examines people’s ability to discriminate between authentic and manipulated images. Advances in digital technology mean that the creation of visually compelling photographic fakes is growing at an incredible speed. Despite the prevalence of manipulated photos in our everyday lives, there is a lack of research directly investigating the applied question of people’s ability to detect photo forgeries. The research in Chapter 3 addresses this question. Across two experiments, people showed an extremely limited ability to detect and locate manipulations of real-world scenes. Chapters 4 and 5 explore ways that might help people to detect image forgeries. Specifically, the research investigates the extent to which people can identify inconsistencies in shadows and reflections. The results suggest that people are reasonably insensitive to shadow and reflection information and indicate that such image properties might not help people to distinguish between authentic images and manipulated ones. Part Two of this thesis examines how the act of taking photos can affect people’s memory. Digital technology has revolutionised the ease with which people capture photos and accordingly there has been a remarkable rise in the number of photos that people take. The results of five experiments and a mini meta-analysis suggest that taking photos has only a small, or plausibly no, effect on people’s memories.