A black line across the film is most likely produced by which processing problem?

• A. Film bent or folded during processing
• B. Fogged film
• C. Reversed film
• D. Collimator angulation too steep

Answer: (A)

Processing artifacts from mechanical handling often show up as a straight, narrow black line across the film when it’s bent or folded during development. The crease alters how the emulsion is exposed and developed in that area, creating a localized change in density that appears as a dark line running across the image. Other problems produce different patterns—for example, fogging would darken the whole film, a reversed image would invert densities, and incorrect collimator angulation causes edge cut-off or distortion rather than a single line.