NTSC
National Television Standards Committee 



Aspect Ratio                4:3
Resolution            450 x 340 Useable Analog
                     (640 x 480 Digital-Pixels)

Channel Allocation            6 MHz
Video Bandwidth             4.2 MHz
Horizontal Freq.      15.734264 KHz
Vertical Freq.            59.94 Hz
Vertical Scan Lines         525
  (Interlace)               262.5


Chroma Subcarrier      3.579545 MHz  (H/2 x 455)
   I Bandwidth              1.5 MHz  123° (Flesh)
   Q Bandwidth               .5 MHz   33° (Indigo)

 Sound
 (L+R) Subcarrier        4.4999 MHz  (H x 286) FM ±50 KHz Deviation
 (L-R) Subcarrier     31.468528 KHz  (H x 2) AM-SC on the (L+R) Subcarrier

Luminance Weighting

Red (R)29.9 %
Green (G) 58.7 %
Blue (B) 11.4 %

Luma (Y) = 0.299 × Red   +  0.587 × Green   +  0.114 × Blue


Chrominance Weighting

(R-Y) 90°87.7 %
(B-Y) 0° 49.3 %

Chroma = 0.877(R-Y) × (3.58 MHz @ 90°)   +  0.493(B-Y) × (3.58 MHz @ 0°)


Timings
Horizontal         Vertical        
Scan 63.55 µS          Scan 16.68 mS
Image 53.39 µS          Image 15.25 mS
Front Porch 1.270 µS          Front Porch 190.7 µS
Sync Pulse 5.080 µS          Sync Pulse 190.7 µS
Back Porch 3.800 µS          Back Porch 1.049 mS
Blank 10.16 µS          Blank 1.430 mS


Adjusted Luma-Chroma P-P Values
  Luma 0.935 0.867 0.757 0.689 0.586 0.518 0.408 0.340
Luma
Grayscale		 100% 88.6% 70.1% 58.7% 41.3% 29.9% 11.4% 0%
Chroma p-p 0 0.533 0.752 0.703 0.703 0.752 0.533 0
Chroma Phase - - 167.1° 283.48° 240.66° 60.65° 103.48° 347.1° - -
Chroma + 0.935 1.134 1.133 1.041 0.937 0.894 0.674 0.340
100%
Saturated
Colors		 White Yellow Cyan Green Magenta Red Blue Black
Chroma - 0.935 0.601 0.381 0.338 0.234 0.142 0.141 0.340



Scope Signals
[NTSC OscilloScope] [NTSC VectorScope]
OscilloScope Vector Scope

I @ 123° Q @ 33°



J. S. Gilstrap Copyright © 2000 All Rights Reserved.