Question on Color Test Pattern

. . . namely, the accuracy of the colors (hue, tint, etc.) of this famous pattern, for those frequenting this forum who worked in the TV industry "way back when":



I seem to remember this variation dated to the mid-1960's or so, coinciding with the major networks and TV stations across the country "making the plunge," as it were, in going color; one of the earliest stations to use it was WFLD in Chicago, IL which first went on the air in 1966. Anyone remember which New York City-area stations could've used this? I have a vague memory of WOR-TV in New York using it (only with their 1970-83 logo variation on the inner lower right quad), as well as WNJU-TV Ch. 47 in Linden/Newark, NJ.

 

Philadelphia's local channel 48, then WKBS-TV, owned by the Field Brothers, used that circular color test pattern prior to sign on in the mid '60s.

Harry

 

Must've been from when Kaiser owned Ch. 48, as Field didn't come in until 1977-78.

But I see one other Windy City station is verified to have used this style of pattern: the ABC O&O, WLS-TV (Ch. 7), as in the form shown in the link below from 1974 (the year the station started transmitting from the Sears Tower) to the 1980's - I have to warn, there is massive discoloration due to age, fading, probably used/worn out camera tubes in the slide chain, whatever:
http://www.youtube.com/watch?v=Qu1yhcgytiQ
Not surprising, given that this was from 1983 . . .

Other stations that I know of which used this pattern: WHBF-TV (Ch. 4) in Rock Island, IL; KAET-TV (Ch. 8) in Phoenix (albeit in B&W); WYTV (Ch. 33) in Youngstown, OH; and WOUC-TV (Ch. 44) in Athens/Cambridge, OH.

If anyone else knows which other stations besides those mentioned here used it, I'd be glad to know - and also, again, if the hues/saturations/intensities are on or off base (I wouldn't depend on WLS' pattern due to the issues I mentioned).

 

Right. Kaiser first, then Field Communications.

 

WFLD was owned by Field in the mid 60's - Kaiser hooked up with Field in the early 70's, didn't they?

 

1972, to be precise. In those years WFLD's "32" logo had the type font associated with Kaiser stations. Field regained full control of Ch. 32 after buying out Kaiser in 1977.

But anyone out there know which other stations used this color TP variation?

 

As you're asking about the accuracy of the colors, I'm curious where this actual graphic came from.

Based on the current measuring of color accuracy from SMPTE color bars, this pattern wouldn't generate the same targets on a vectorscope, particularly that green. What measuring they were doing circa 1966, I can't say.

 

Interesting...never saw the color version of that TP. I know for a fact that WCBS-TV Channel 2 in NY City used the B&W version of that for YEARS, but I don't recall ever seeing a color version.

 

Don't know if this helps but here's an old WABC test pattern. There are some other "test pattern classics" at this site:
http://www.ggninfo.com/TP6.htm

 

That was one of two layouts of this pattern - the color arrangement of which dates to c.1980 - that was used by WABC. This, obviously, was one. The other layout, as of 1983, with this exact same color scheme, had "WABC-TV" in News Gothic Bold on the top left, "New York, N.Y." (upper and lower case) on one line in the same typeface on the top right, a printed "7" in white over the center bullseye rather than the logo, and "American Broadcasting Companies, Inc." in what looked like Univers 65 all through the bottom, even going through the bottom vertical-resolution wedge.

I saw the vintage recreations on that site you mentioned. As far as that for WLS-TV in Chicago goes, they were way off - especially as the station first transmitted from the Sears Tower in 1974, not long after it opened, and they used a color T.P. at the time as per that YouTube link (whereas the recreation was in black-and-white, and the type layout was far more disorganized than that on the actual pattern).

As to where the graphic came from - my estimation is it could've come from what was originated by NBC in 1941 when commercial, 525-line television first started, and had about four modifications over the years (including the two color variations, as well as a 1947 pattern for what was then WNBT in New York [now WNBC] where they had actual technical descriptions on how much lines equalled what, and the different amount of MC's [now MHz]). You can see such pattern by Googling "NBC Test Pattern."

And WCBS's test pattern was much different, though along these lines. The five-step black-to-white gradations took up the upper and lower quads, with one big white circular target in the center on which the call letters and city were displayed - kind of reminded me of an abstract of an LP record with strapping tape to hold it together, actually. (The other CBS O&O's - WBBM-TV in Chicago and KNXT [now KCBS-TV] in Los Angeles - plus other stations they owned in the past, such as WCAU-TV in Philadelphia, WGTH-TV [later WHCT, now WUVN] in Hartford, CT, and KMOX-TV [now KMOV] in St. Louis - also used this pattern, as did a few primary and secondary CBS affiliates across the country.)

As for those color circular patterns, I wouldn't be surprised if it were all based on guesstimate work, using either Pantone colors or whatever was on hand. Some of the colors were seen on various slides of I.D.'s, program promos, etc. SMPTE's color bars didn't first show up until the 1970's (first as ECR 1-1978, then followed by EG 1-1990), before that there was EIA color bars. And those had many variations in shape before the standardization.

And since I have access to video editing equipment - even down to a waveform monitor/vectorscope (don't ask me how), I can attest to what you're saying about the colors of the circular patterns not necessarily measuring up to EIA or SMPTE color bars in the accuracy department.

 

Wow.

It still amazes me how much a person can learn
from others on this board.

But I also understand that some of these test patterns
got higher ratings than CBS's recent "Viva Laughlin".

 

Actually, that was one of two TV stations in New York to have used that pattern variant, which dated to the early 1980's; the other being WPIX. Two Boston TV outlets (WSBK and WNEV, the latter formerly WNAC and now WHDH) also utilized this pattern, the full version of which is below:



As to the 1960's variation, I've since learnt that the colors, tints, et al., were more like this:



Besides the other stations mentioned, this was also confirmed to have been used by WSMW-TV (later WHLL, now WUNI) in Worcester, MA, and WLVI-TV in Cambridge/Boston, MA.

 

Has anyone figured out exactly what the colors in these patterns were used for? Or I suppose, more accurately, how they were used? The black and white sections on each end are likely to indicate black level and peak white. The grayscale rings appear to be 0%, 25%, 50%, 75% and 100% brightness. The wedges can be used to detect resolution limitations.

 

It should be noted that the colors on these patterns varied in appearance due to a host of factors including the way the slide was developed, its age and possible color fading (with even the greyscale affected to the point where it appeared greenish, bluish, reddish, brownish et al., unlike with the BBC where they had a double-level slide, the famed girl with a clown doll with "X's and O's" on a blackboard (and colors on the outer edges) printed in color while the greyscale was in black-and-white), the calibrations of the color tubes in the slide/film camera chain, and so forth. I figure that in the '60's color pattern, the really dark blue and dark purple were an approximation of the -I and +Q calibrations, respectively, though even that wasn't necessarily a match. But generally, the colors appeared more for show rather than actual calibration per electronically-generated EIA or SMPTE color bars which eventually replaced either or both of these patterns. They were, however, very ubiquitous while they lasted.

 

In case one can't see the (recreated) samples, here they are again:

 

Brings to mind the line I'd heard about what NTSC meant: "Never The Same Color."

 

The colors mean very little unless you have a vectorscope. With a vectorscope, you'd be able to check color phase, intensity, and certain kinds of errors. Most analog test patterns are set for 75% chroma intensity, which is standard for NTSC. (SMPTE color bars, showing alternate hues next to each other, can let you adjust hue if you have a "blue-only" mode or a blue filter.)

The B&W wedges theoretically showed bandwidth by means of resolution. Those you could check on a waveform monitor, and check to see how flat the signal was out to about 3.58 MHz. Usually, everything rolled off pretty fast after that, depending on whether a notch or a comb filter was used in the circuitry.

This is all real old school stuff that doesn't apply to anything in 2008. Digital recording and transmission is many times more accurate for video, assuming no compression artifacts or design flaws.

 

Ironically enough, none of these jpegs of patterns show cyan!

 

Or Never Twice (the) Same Color. Always good for a chuckle.




Dan

 

Those circular color wedge test patterns (or CWTP's in Worldwide TV-FX DX Association [WTFDA] parlance) were offered (for sale, of course) by a company in Clifton, NJ (that's still around) called Tele-Measurements, Inc. As of the mid-1970's, that pattern was designated TM-501 in their 'Tele-Pat' series. It was used all over the U.S. and even abroad (one station in El Salvador used it), but for some reason what we see via YouTube and other sites was primarily concentrated within the Eastern Seaboard and Midwest. Very few evidence of such patterns in use at stations west of the Mississippi (with K calls) is available today, though no doubt they were used. An ad they put out in 1977 that ran in such trade publications as BM/E and Broadcast Engineering showed one example of this pattern at work - for KQEC (formerly KSAN and KNEW, now KMTP) Channel 32 in San Francisco. While test patterns held sway for video geeks such as myself and 'ChipTRG', unfortunately too many were of the "Test patterns are soooo boring" mindset and thus didn't commit them to tape (Beta, of course, or VHS after the '80's) or photograph them for DX'ing purposes.