First photograph (not tintype) 1835. Tintypes were popular because they were simple enough to make that itinerant photographers could make a living traveling and selling their services. Cameras and development paraphernalia were much more involved and cumbersome.
I agree with your methodology for forming an opinion on images. It's not a science.
In this case I don't think there's that much of a difference in the orientation of the head with respect to the lens. I think it's about as good a match as is likely between two photos of the same guy.
The expressions on the face appear to be different--this could account for mouth differences and the level of the focal point of the subject's eyes.
I think the match is pretty good all things considered, but I would not say the match is perfect enough to take a definite stand on the ID.
Jerry, I think (and I may be wrong but I'm fairly sure) that the comparison photo I posted shows Billy and the new guy as they posed in life. Fortunately, the other guy in the new photo is wearing... more
invention of photography Jerry Lobdill,Sat Apr 21 08:08
I think the two photos (1 tintype) look quite a lot alike. Several years ago Scientific American or the Smithsonian Magazine did an analysis of the BTK Photo and a photo of Brushy Bill of Hico,Texas... more
One of the BTK documentaries did a similar analysis (maybe the same one you referenced?) and came to the same conclusion. The authenticated tintype (which some actually doubt is really BTK) shows a... more