Pi Lines artifact is described as lines that appear at regular intervals due to a dirty roller.

Pi Lines artifact is described as lines that appear at regular intervals due to a dirty roller.

• A. Lines that appear at regular 3.14 inch intervals caused by a dirty roller
• B. Lines that appear due to cloudiness in film emulsion
• C. Lines that appear due to insufficient exposure
• D. Lines that indicate improper chemical concentration

Answer: (A)

Pi Lines are a processing artifact. They show up as parallel lines at regular intervals on a film because a dirty or rough roller in the film processor leaves marks each time the film passes through. The spacing between the lines corresponds to the roller’s circumference, which is pi times the roller diameter. If the roller is about 1 inch in diameter, that spacing is about 3.14 inches, which is why the lines are described as occurring at regular 3.14 inch intervals. This pattern points to rollers’ condition in the processor, not to emulsion cloudiness, exposure level, or chemical concentration—those issues produce overall fogging, density changes, or contrast problems rather than evenly spaced lines.

Pi Lines are a processing artifact. They show up as parallel lines at regular intervals on a film because a dirty or rough roller in the film processor leaves marks each time the film passes through. The spacing between the lines corresponds to the roller’s circumference, which is pi times the roller diameter. If the roller is about 1 inch in diameter, that spacing is about 3.14 inches, which is why the lines are described as occurring at regular 3.14 inch intervals. This pattern points to rollers’ condition in the processor, not to emulsion cloudiness, exposure level, or chemical concentration—those issues produce overall fogging, density changes, or contrast problems rather than evenly spaced lines.