Shroud Solo Show (Part 11)- Sunlight-Based Hypotheses (Proto-Photo, Shadow & Solar Reflex Models)

In Part 11, I continue my analysis of the various "Ordinary Artistic" image-forming mechanisms/hypotheses, specifically focusing on hypotheses based on the invovlement of sunlight as the image-encoding mechanism.  There are three fundamental types of such hypotheses; i) The Medieval Proto-Photograph (Proto-Photo) models (Piknett & Prince and Nicholas Allen), ii) Nathan D. Wilson's "Shadow" model and finally, iii) Serge N. Mouraviev's Solar Reflex model.