Cascadia Digital video recorder Instrukcja Użytkownika Pobierz pdf (Strona 25)

CCTV Glossary

Cascadia Video Products LLC

25 / 43

Noise - An unwanted signal produced by all electrical circuits working above the absolute zero.

Noise cannot be eliminated but only minimized.

Non-drop frame time code - SMPTE time code format that continuously counts a full 30 frames

per second. Because NTSC video does not operate at exactly 30 frames per second, non-drop-

frame time code will count 108 more frames in one hour than actually occur in the NTSC video in

one hour. The result is incorrect synchronization of time code with clock time. Drop-frame time

code solves this problem by skipping or dropping 2 frame numbers per minute, except at the tens

of the minute count.

Noninterlaced - The process of scanning whereby every line in the picture is scanned during the

vertical sweep.

NTSC - National Television System Committee. American committee that set the standards for

color television as used today in the US, Canada, Japan and parts of South America. NTSC

television uses a 3.57945 MHz sub-carrier whose phase varies with the instantaneous hue of the

televised color and whose amplitude varies with the instantaneous saturation of the color. NTSC

employs 525 lines per frame and 59.94 fields per second.

Numerical aperture - A number that defines the light gathering ability of a specific fiber. The

numerical aperture is equal to the sine of the maximum acceptance angle.

1 2 ... 20 21 22 23 24 25 26 27 28 29 30 ... 42 43

Brak uwag

Cascadia Digital video recorder Instrukcja Użytkownika Strona 25