Making a copy negative is pretty simple, although there are a few ways to do it.
Film whether it was glass plate or film, came in both negative and positive versions. Think slide film, which is positive film developed and used directly in slides.
That could be bought not only in camera film sizes, but in sheets. The same for negative film.
(Or for some films, it's the same emulsion but developed differently.)
With an original negative in an enlarger, just expose it onto the right film, develop properly and there's your copy negative. (Can also be done as a contact print.)
If you're making hundreds of prints, it's good practice to generate a copy negative to do production with so the original doesn't get damaged.
If the person doing the copying is really good, it can be hard to tell, especially if the original and the copy are both film. Even moreso if they get sneaky and do a film to film contact print with the emulsion sides together.
Lots of ways to play around with stuff in a professional darkroom.
Halftones are done by photographing an original through a screen.
|