- X sync socket
- Better cameras have an X sync socket which looks like small metal circle inside a silver ring. Like a hot shoe it's used to attach an external flash unit to a camera. Most photographic studio lighting is synchronized with the camera shutter by a cable attached to the camera's X sync socket.
- x-ray machines at airports
- Modern x-ray systems used in airports to check hand luggage do not harm photographic film. If you are travelling to less developed countries where the x-ray machines may be older ask to have your films checked by hand or use a special lead-lined bag to protect your film. Stronger and potentially damaging x-rays are used on suitcases and luggage kept in the plane's hold so always carry film in your hand luggage.
- Xerox
- A generic name referring to the output from color laser copiers (CLC's)
