|Image by kind permission of Krzysztof (Kriss) Szkurlatowski|
Static electricity can be a problem in a range of environments. Most people have experienced minor electric shocks received when touching elevator buttons and other metal surfaces. Discharges of this type are caused by a build-up of electric charge on the body, perhaps by walking across a carpet made of synthetic fibres. Fingers extended to earthed metal surfaces then become a conduit for high-voltage, low current discharge and a spark may be seen to pass between the body and the earthed surface.
Static discharge is hazardous to film because it can cause streaks on unprocessed film. Static electricity is similar to lightning in miniature, and commonly leaves a series of white or blue dots in a random or zigzag pattern. It is also hazardous for delicate electronic components such as those found in computers, digital cameras and hard disks. It is always advisable to discharge oneself by touching an earthed bare metal surface such as a tap or water pipe before dealing with electronic components.