In the film world, there is positive and negative film, but each must be converted into a print form. One method used by Dieter Kohn on Worth Avenue in Palm Beach, Florida skips the film phase altogether – directly exposing Kodak Ektacolor paper for a ready to go, full-size print moments after capture.
This craziness is only possible with the help of a 500lb large format view camera. Kohn got the idea originally years a before he actually put it into use, but he ran into a snag. The Kodak paper he wanted to expose for the direct prints had an ASA (ISO) equivalent rating of 5-7. In other words, it required a ton of light in order to get a proper exposure.