How Does an electromagnetic field affect the performance of an infrared surveillance camera?

Answer 1

It depends on field strength. For most consumer grade units, they are tested to withstand a 3V/m field over a range of 30-1000Mhz, in most cases, assuming near perfect wiring practice. Some manufacturers are likely better than others. Once you get above 3V/m or over 1000Mhz, it may or may not work. Failure systems range from occasional drop outs and lockups to total lockup, and if the field is strong enough catastrophic failure can result. Improper wiring practices can result in significant performance degradation.