One of the most common and yet also most preventable problems in the radiology department is unnecessary darkroom fogging of x-ray film, which can degrade image quality to the extent that the procedure must be repeated. Such problems can be overcome by identifying and eliminating sources of fog, such as incorrect safelight filters, excessive safelight wattage, using too many safelights or placing them too close to the work area, light leaks, and indicator lights on telephones, silver recovery units, timers, or other electrical devices.