A careful reader may notice Camera Lucida (Roland Barthes, 1979) rests many of its claims on the author's unique, intellectual constructs. Barthes can't avoid his self-absorbed way of exhausting an elaboration; his understanding of the truth in photography is a strange brew of phenomenology and ontology and self-indulgence.
Photographers and artists will find this short and often-brilliant volume maddening; Barthes can be pretty naive about crucial aspects of making photographs and images. I prefer Susan Sontag's two volumes, On Photography (1977) and Regarding the Pain of Others (2003.)