Film Artifacts, such as crimps, can appear as cracks or other defects
on the film. To better understand how they look on the film perform
the following exercise.
- When loading a piece of film, make a pronounced bend or crimp in
- Produce a radiograph with a density between 2.0 and 3.0 of a sample
- When removing the exposed film from the cassette for developing,
make a second bend or crimp in the film some distance from the first.
Make sure that you can distinguish between the before exposure artifact
and the after exposure artifact.
- Develop the film and examine the radiograph.
- Note the differences in the two crimps. Which of the crimps appear
more like a crack?
Given enough time, film can be exposed by the safelight
in the darkroom. In this example use a class 2 film, as it will more
readily demonstrate the effects.
- After the safelights have warmed up for at least ten minutes place
a opaque covering over one-half of the film. On the exposed half place
lead letters, or other opaque objects. Allow the film to be exposed
under the safelight for a period of fifteen minutes.
- Remove the opaque covering from the film while leaving the opaque
letters or objects in place on the other half of the film. Allow the
film to remain in the light for another fifteen minutes.
- Process the film and evaluate.
- Note the effects of the safelight on the two halves of the film.