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Never Twice the Same Color: Time to get rid of NTSC

technofile  by al fasoldt

Columns and commentaries in a life-long dance with technology
 

Simple gray rule



Never Twice the Same Color: Time to get rid of NTSC 


By Al Fasoldt

Copyright © 1989, The Syracuse Newspapers

High Definition TV is wonderful and we'll all love it. That's the impression I came away with after seeing a dozen displays of HDTV at the Summer Consumer Electronics Show earlier this month.

But I was reminded of another aspect of the coming revolution in television when I looked at row after row of regular TVs at the annual Chicago trade show.

I realized from looking at their screens that HDTV will be a blessed event for thousands of American, Canadian and Japanese videophiles—not necessarily for what it will bring, but for what it will do away with.

It will finally get rid of the dreaded NTSC.

That's not a disease or some kind of parasite. It's the name of the present color television system, which has been inferior since the day it was born.

When "radio with pictures" was being developed in the 1920s and 1930s, engineers had one basic goal: to make a picture with good detail, sharpness, brightness and contrast.

But experiments with color TV in the late 1940s added a new element and it became clear that any system of broadcasting color pictures would pose a problem for those who had only black-and-white TVs.

The Columbia Broadcasting System came up with a color system that worked extremely well in every area except one—its picture could not be viewed properly on non-color sets. The CBS design had many supporters.

But CBS's rival, RCA, figured out a way to send out a color signal that looked like black-and-white on older sets. RCA did this by cheating on the color: It combined the color and brightness sections of the color picture into a single electrical carrier.

It was A brilliant compromise, at least in theory. Color TV sets would take the signal and separate the color and brightness sections back to where they should be.

Black-and-white sets—which lacked the special circuit needed to split the two elements—would respond only to the brightness part of the signal.

RCA's method was chosen by a government body called the National Television Standards Committee. The FCC then decreed that this NTSC-backed system had to be used in all color sets.

The governments of Canada and Japan made the same stipulation. Canada had no choice, because most of its programming at that time—the early 1950s—came from the United States. Japan made its choice under pressure from the United States, which had defeated Japan in war a few years before.

In practice, RCA's design was badly flawed. The two signals didn't get along well together and what viewers saw—and still see in all of the regular sets in use even today—is a picture in which colors change as the image gets brighter or darker.

What's more, the brightness of a scene changes along with the color.

Punsters quickly changed the name of the NTSC system to Never Twice the Same Color, and engineers fumed.

But their trials are coming to an end. In all HDTV systems that have been developed or proposed, the two signals are kept a safe distance apart. And since there is no such thing as black-and-white HDTV, compatibility with black-and-white sets is not a concern.


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