>>Indeed, attempts at photography are going to be pretty futile before
>the invention of charged coupled devices, unless someone has invented
>a photographic process that involves some magical medium rather than
>silver halides.

Minor note, there are a number of non-silver photographic processes that predate the time the story is set in.

https://en.wikipedia.org/wiki/Alternative_process
https://printedpicture.artgallery.yale.edu/non-silver-processes

-VR
Cyanotype probably wouldn't give a desired effect though.
"They copied all they could follow, but they couldn't copy my mind,
And I left 'em sweating and stealing a year and a half behind."