A photographic image obtained without the use of a camera, by placing objects on a photosensitive surface (paper or photographic film) and then exposing it directly to light.
Inspired by the work of Man Ray, “Rayography”, from which it takes its name, is a “photograph obtained simply by placing the object between the sensitive paper and the light source”.
Man Ray says: “Captured in moments of visual detachment, during periods of emotional contact, these images are the oxidations of residues, fixed by light and chemistry, of living organisms. “(quote from Man Ray, Self-portrait, 1963, Actes Sud, 1998).
In fact, if you look closely at the little white dot, it is a tiny insect that was passing in front of the light source.