Film Artifacts

An artifact is defined as any irregular density or opacity on the film. There are three main types of film artifacts: exposure artifacts, handling artifacts, and processing artifacts.

Exposure Artifacts

Exposure artifacts are radiographer-related. Examples include: wrong film in cassette (mammography film in a regular cassette); double exposed film; and motion due to poor instructions to the patient.

Handling Artifacts

Handling artifacts are more prevalent in winter and with a change in humidity. Static (crown, tree and smudge) is caused by a buildup of electrons in the emulsion and occur when the film is dragged across the surface of the darkroom work surface before it is placed in the cassette. To prevent this, the work surface must be grounded. Dark lines (marks) on a radiograph can be caused by pressure. Marks caused by fingernails look like half moons and marks in the corner of the film is caused by bending it before it is placed in a cassette.

Processing Artifacts

Processing artifacts occur as a result of automatic processor problems. Guide shoe marks are scratches found on the leading or trailing edge of the film and run parallel to film travel. Pi lines are film artifacts caused by chemical buildup from dirty rollers. Pick off is film artifact caused by little pieces of emulsion that stick to the rollers and is picked off by a passing film. An uneven or streaky sheen on the film is caused by uneven drying or poor alignment of squeegee rollers.

The developing solution can be the cause of processing artifacts. Excessive density can be caused by the developer temperature being too high or the developing agents are too active (lack of restrainer after cleaning). Inadequate density can be caused by the developer temperature being too low or the excessive dilution of the developing solution. Finally, the loss of contrast on a film can be caused by the developer temperature being too high.

The fixing solution can also be the cause of processing artifacts. Low fixer concentrations can result in sticky films caused by poor hardening of the emulsion; milky films caused by residual developer in the emulsion; and eventual browning or yellowing of films caused by the oxidation of developer left in the emulsion. High fixer concentrations can result in a brittle, cracking emulsion caused by excessive hardening of the emulsion.

Damp films are also considered a processing artifact. Damp films can be caused by the dryer temperature being too low; a faulty dryer blower; or inadequate fixing caused by poor hardening of the emulsion.

The development of unexposed AgBr crystals decreases contrast and increases density. This can be caused by higher development temperature and longer time in tank. It can also be caused by a weak restrainer resulting in not enough potassium bromide to control aggressive developing agents. Finally, it can be caused by over replenishment when the rate is set too high or the system has malfunctioned.