Registering film for printing (optical) isn’t a mystery. It is simple, but has changed, with increasing complexity of mechanism making easier, more certain, faster production of picture.
At first, the method was: cut-n-butt. This was the way wash-off relief (dye transfer) was done. And done for 15 years.
Printers and animators had other means and methods. More about that in the “registration” posts.
photography began as small, which meant it had to have details
because it was precious personal small… miniature, momento
small enough to carry, like a smartphone. smooth, polished, thin, like a smartphone
something that was shared with heads bent toward it, like a smartphone at a table
photgraphry stopped time and traveled across space. traveling by bringing end points together
like the web
photgraphy left objecthood centuries ago
objecthood is sculpture, is painting striving for its canvas – sculpture has walked off the plynth, painting from above the couch replaced by big as life postcards from the camera