Neutral Density Filter – a lens filter that reduces the intensity of light without affecting the color of the light.
NFL - A film or stage floodlight designation that calls for a "narrow" flood lamp. See: Stage Lighting Equipment.
Normalization – the process of adjusting the levels of a digital signal so that all frequencies are reproduced at a proper level.
NSP – A film or stage spotlight designation that calls for a "narrow" spot light. See: Stage Lighting Equipment.
NTSC – an acronym for National Television System Committee. In the 1960s this committee set the standards on our television signals would be transmitted and reproduced.
Nyquist theorem – a theory that states that the sampling rate of a signal must be at least twice the highest frequency that needs to be reproduced.