NTSC and PAL

[johnbasalla]

What does NTSC and PAL stand for? How relevant are they in the HD/digital age?

 

[Tom Wells]

I used to actually remember what NTSC stod for, but the old joke is that it stands for "Never The Same Color", a dig at the problems found in separating the luminance from the "chrominance" info in early color TVs.
This is also why early color TV shows (think Star Trek) favored lots of big swaths of "easy" reds, greens, and blues.

It became a lot easier in solid-state design but the name stuck.

I'd love to see what color looked like on the old CBS mechanical wheel color system.

 

[landtuna]

What does NTSC and PAL stand for? How relevant are they in the HD/digital age?

Here's a pretty complete definition: http://www.michaeldvd.com.au/Articles/PALvsNTSC/PALvsNTSC.asp

 

[w9wi]

What does NTSC and PAL stand for? How relevant are they in the HD/digital age?

NTSC = National Television Systems Committee.
PAL = Phase Alternating Line.

PAL is fairly similar to NTSC, differing mainly in that the phase of the color subcarrier is flipped over on every line. That causes most phase errors in transmission to cancel out. (in NTSC, a phase error results in part or all of the screen having the wrong hue. In PAL the color saturation drops -- it's a lot less noticeable. On the other hand, PAL studio equipment and receivers are more complex. Not an issue today but it was a real issue in the 1950s. Indeed, NTSC considered phase alternation but decided not to.

The concept of transmitting the black-and-white information in the widest possible bandwidth and using half-bandwidth for color was developed by the NTSC and is used today in digital TV. So is the matrixing system, where luminance, red, and blue are transmitted. (but not green. It can be calculated from the other three.) The frame rates used with NTSC and PAL (29.97 for NTSC, 25 for PAL) are also used for DTV.

But that's just scraps. A very large part of both NTSC and PAL are gone with digitization.

 

[rfry]

...I'd love to see what color looked like on the old CBS mechanical wheel color system.

Maybe you have, if you've seen the archival CBS field-sequential (color wheel) video sent back from one of the moon landings. When the lander left the moon it created a lot of bright white "blastoff" debris, which showed on a CBS color set as a trail of alternating spots of pure red, green and blue. The same would be true for any white or nearly white object traveling fast across the frame (golf ball, baseball, etc).

The CBS system also had an annoying visual flicker (at about 20 Hz) in areas of the televised scene containing only primary colors (R, G, or B), and colors close to them.

NTSC does not have such color artifacts, because as generated/transmitted/displayed, it contains the true* and final color for each pixel in the scene. NTSC is a simultaneous system, not a sequential system.

* assuming a transmission path with little/no differential phase and gain. The fact that such transmission paths did not have such characteristics in the early days of color television was responsible for the color problems leading to the "Never Twice the Same Color" definition for NTSC.

Such path problems were overcome decades ago, however, and after that most people never found the need to tweak the color controls on an NTSC TV set.

//

 

[Tom Wells]

Ahh yes, the fine old days when color TVs had controls for TINT and HUE!
(Had to fine adjust them greens)
Not only did most people NOT adjust their color, they shouldn't have been allowed to, as most Hotel TVs were blocked from this
function. The average consumer would turn the color and contrast up way too high.
The 3.58 osc for color sync in most TVs put out a LOT of horrible spurs in the MW band.
As well as the 14,758 hz horizontal sweep audio noise, if your hearing goes up that far.
For these reasons, I'm kinda glad NTSC is gone.

 

[littlejohn]

NTSC: Never Twice Same Color
PAL Pretty Awful Looking.

Actually, the two systems are pretty identical save that PAL inverts the phase of each sucseseive scan line so that chrominance errors due to phase shift will tend to cancel. This requires a delay line and a bit of extra circuitry in the receiver, increasing the cost. At the time color TV appeared ('pioneered and develpoed by RCA'), AT&T assured NTSC and the networks that they could deliver a TV signal coast to coast with 5 degrees or less of phase shift across the passband. This meant that backhaul and carriage chrominance errors would be (hopefully) minimal, and thus the receivers could skip the line alternation and be manufactured a bit cheaper.
As a point of interest, if you had a good VCR and a monitor which had decent rage on the horizontal and vertical oscillators, you could sort of view European pron in this country. Flickered but was viewable. Not, of course, that any of us >did<, but you >could<.

 

[streamer]

Many moons ago, in my BBC Engineering Training Classes at Wood Norton (oh what great training), how we remembered was

NTSC - Never Twice the Same Colo(u)r
PAL - Perfection At Last (tongue in cheek, they went through the advantages and disadvantages)
SECAM - They Seek'em here, they seek'em there, the French seek the color everywhere.

Then we got into how we could have NTSC line rates and Subcarriers but PAL color burst and also 625 lines but NTSC subcarriers etc. Ah, the world standards...

It was described that only true interchangeable media standard for the world was a 35mm film print!! Still not that far these days! At least in Europe we didn't have to mess with drop-frames! but 8-field PAL editing could be a nightmare if on 1" Tape....

 

[rfry]

SECAM - They Seek'em here, they seek'em there, the French seek the color everywhere.

Another form was "Something Essentially Contrary to the American Method."

RF

 

[Tom Wells]

SECAM - They Seek'em here, they seek'em there, the French seek the color everywhere.

Another form was "Something Essentially Contrary to the American Method."

RF

The very essence of everything that is french. French scematics are truly a wonder. Similar to German, but with its own special way of
obfuscation.