Sheet film
Sheet film (rarely: sheet film) is film in sheets that is not rolled. It is used in large format cameras (also called sheet film cameras ) and in pinhole cameras , usually using a sheet film cassette . Polaroid's instant films can also be classified in the flat film category.
use
Working with sheet film is relatively easy and inexpensive. Flat film is mainly used for advertising , food , industrial and architectural photography, where a wide range of setting options and complex lighting are necessary.
Sheet film is also used in the photo laboratory for duplicating , reproducing , masking , sound separation and copying .
The layer side of a sheet of film is indicated by notches in the same. The layer side faces the viewer when he feels the notches at the top right (in portrait format). The film is loaded into a film cassette. Then this is closed with a slide. The slide is only pulled out shortly before exposure and then pushed back in. Each type of film has its own combination of notches and spikes so that the skilled photographer or assistant can identify the type of film when loading and unloading in the darkroom.
From the 1920s, medium-format photography and, from the 1930s, 35mm photography prevailed. Since the spread of digital photography , digital backs for sheet film cameras , for example from Sinar or Linhof , have been offered.
processing
Sheet film can be processed in our own photo laboratory. Trays or development boxes of the appropriate size are required; Instead of spirals, the devices must be equipped with sheet film holders.
In the professional photo laboratory, sheet films are processed in tanks with special developing machines, in which the films are hung with a frame ( tank development ).
History and Development
The glass plates of the wet collodion process used in the early days of photography and later the gelatine dry plate were replaced by the Hyatt brothers' celluloid . The inventor of the photographic sheet film was Hannibal Goodwin . The new type of substrate was flexible, unbreakable and light. In July 1888, if not earlier, John Carbutt , Philadelphia, planed sheet films from blocks of celluloid, which he coated photographically. The celluloid also made it possible to produce roll film and motion picture film .
Formats
Flat film is produced in numerous formats. The dimensions that used to be very common are:
- 9 cm × 12 cm
- 13 cm × 18 cm
Today the market has shrunk a lot, inches are the most common:
- 6.5 cm x 9 cm
- 4 "× 5" (10.16 cm × 12.7 cm)
- 5 "× 7" (12.7 cm × 17.78 cm)
- 18 cm × 24 cm
- 8 "× 10" (20.32 cm × 25.4 cm)
- 11 "× 14" (27.94 cm × 35.56 cm)
Usually boxes with 10, 25 or 50 sheet films are offered. The boxes are made up of three parts and consist of low cardboard boxes that are stacked one inside the other. The film material itself is packed in a tear-off light protection cover. The film foils have notches on the edge (see picture above), which allow the type of film to be identified in the dark.
With sizes from 9 cm × 12 cm to 20.32 cm × 25.4 cm (8 "× 10") one speaks in photography of large format, above that of oversize or ULF (Ultra Large Format.)
See also
literature
- Elizabeth Brayer: George Eastman: A Biography . Johns Hopkins University Press, 1996.
- Ernst A. Weber: Photo internship . (3rd revised and expanded edition). Birkhäuser-Verlag, 1997. ISBN 3-7643-5677-4 .