In this presentation I discuss some preliminary findings fråm an experimental reception study performed at Örebro University as part of y PhD in media and communication (film studies). In my project I have investigated what happens in encounters between the viewing subject (Panagia 2009) and feature films that are difficult to determine in terms of belonging to the genre fiction or documentary, often referred to as mock-documentaries or fake documentaries (Roscoe and Hight 2001; Juhasz and Lerner 2006; Rhodes and Springer 2006). Although these are increasingly becoming established and recognized as putting on a plya with the discourse of factuality associated with the documentary, there are still a number of films defying categorization and recognition and where the recieved blurred boundaries between the factual and the fictive are met with strong affective reactions. By drawing from a transdisciplinary theoretical framwork, new materialism, I use an ethico-onto-epistemological point of departure (Deleuze 1968; Massumi 2002; Barad 2007; Dolphijn and van der Tuin 2012) whereby affective processes are understood as producing materialities of relation of power. By referring to a present 'post-truth atmosphere' (coined as such in an article in the Washington Post 2016) I make the argument that what these encounters with blurred boundaries between the factual and the fictive makes noticable is a current on-going reconfiguration of the regime of truth (Foucault 1977).