I once had someone claim they had found a lost Caravaggio painting that might be worth millions, and wanted me to examine it before they tried to track down an expert on the subject. From clear across the room it looked awfully amateurish to me; but it had the relevant style and symbolism, and it looked old. I told him it might have some secondary historical value as a student copy of some otherwise unknown Caravaggio work. But I was skeptical of even that. So he paid me to do a little of my own forensic work. I took pictures of it on my copy stand using heatlamp lighting, Tech Pan film, and a deep red filter - and sure enough, that revealed underpainting of a Victorian Dogs with Cards theme! No need to spend even more money with the experts. One more bubble burst.