Assessments of the truthfulness or otherwise of documentaries are best understood as genre conventions which vary historically. Genre conventions are shared between audiences, filmmakers and institutions. Beliefs about the acceptable use of fictional techniques in documentary storytelling, particularly in television, are subject to occasional public controversies. The move from photographic to digital processes underlay one such controversy at the end of the last century. This was particularly the case around the so-called ‘docu-soaps’ on television, but public doubts about the truthfulness of documentary filming meant that many filmmakers developed new approaches. The result is that both public and professional documentary beliefs and practices have changed. Where once observational filming was seen as the bedrock of authenticity, newer approaches have developed a growing emphasis on the assessment of the ‘documentation’ of past events. They frequently gather and interrogate footage and other visual information from very diverse sources. They are seen as evidence in explicit attempts to reconstruct those events.