B&W picture is bluish-green

When I watch the "oldies" tv channels, (This TV or Me-Tv) I noticed that all those old Black and white programs are actually black, white, and shades of gray. But when the Patti Duke show comes on every morning on This-Tv, it's bluish-green tinted. It's only that show, all the other B&W shows are really B&W. Some episodes of the Patti Duke show are more tinted than others. Why is this?

Note, this is not just one tv set. I notice it on several tvs, and they are different brand tv sets and converter boxes. They is hooked to rooftop antennas.

Reply to
tangerine3
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possibly converted from film to digital and had the wrong lamp in the converter?

--
?? 100% natural

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Reply to
Jasen Betts

NTSC or digitalized?

I don't know if DTV supports monochrome the same way NTSC did. When an NTSC signal doesn't contain a colorburst subcarrier, the chroma detection is turned off and the set reverts to B&W operation -- tint would be controlled by RGB balance and gain, but these will be correct in a properly adjusted set.

I'd guess digital is always color and the actual color a B&W program has depends on how it was transcoded. It's very easy to apply a filter to a video stream these days, some may simply have different opinions of "white".

Tim

-- Deep Friar: a very philosophical monk. Website:

formatting link

Reply to
Tim Williams

That was a big problem in the early days of Color TV. Stations were supposed to shut off the color subcarrier when transmitting monochrome video, so the color killer circuit in the TV would shut down the chroma circuits.

Reply to
Michael A. Terrell

HOLY CRAP !!!

I know what that means !!!!

;-)

Reply to
hamilton

I know that the local "This-TV" station has some pretty crappy equipment. Maybe this is their doings, even though I can see that there may also be something having to do with the conversion from film to digital. I know for fact the equipment is crappy for this local station because when they first got on the air, their commercials were so loud I'd almost go deaf. I contacted the station and was told they are trying to get the money to buy some device to equalize the sound levels. Months later they finally got one. Then they often have the sound not in sync with the picture, so the lips are not even close. I contacted them about that and was told that their receiver from the satellite has to be constantly re-adjusted daily to keep them in sync, and the tecnician actually told me that their receiver is a piece of shit. That particular day the sound was off by as much as about 8 seconds, and he admitted that was the worst he has seen it.

At the same time, I often watch some old B&W movies, Highway Patrol, Mr. Ed, and other shows and they are true B&W. As soon as Patti Duke comes on, I instantly notice this bluish-green tint. After a few minutes it's not noticable, but when it first comes on, after watching the other (correct) programs, it's sort of a shock to the eyes.

I recall the color killer circuits in the older color TV sets, back when I worked on them in the 60s and 70s. The TVs I have now are all fairly new, but still CRT types that need a DTV converter, and none are HDTV.

Reply to
tangerine3

** You can always turn down the "color" saturation and get a B&W pic.

Wot a whinger....

.... Phil

Reply to
Phil Allison

I'd say it is 100% a problem with their conversion. Most likely they are using DVDs for the video, and the DVD was mastered (converted) incorrectly. There is a remote possibility it was done on purpose, where the original print was tinted (perhaps by age, not intentionally) and they decided to retain that tinting in the digital edition.

--
I'm never going to grow up.
Reply to
PeterD

Someone call Ripley's, QUICK!!! ;-)

Reply to
Michael A. Terrell

Supposed to.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)
Reply to
Fred Abse

Yes. If the station was monchrome only, a chroma trap was required on the transmitter's video modulator to remove any random noise that could trigger the chroma circuits. I had manual switches on both Gates VHS transmitters that I used in the '70s.

A green picture was normal, if the color killer wasn't working.

Reply to
Michael A. Terrell

As far as I'm concerned b&w TVs were never b&w. I noticed this one night walking in the street - from the outside the flickering TVs in peoples' houses looked bluish.

Reply to
Gib Bogle

"Gib Bogle"

** That is an optical illusion created by the differing "colour temps" of (1950s or 60s) incandescent street lighting and the daylight white of TV screens.

.... Phil

Reply to
Phil Allison

Interesting. Makes sense. I once had my mind blown by a talk given by a guy from Polaroid, about the determining influence of context on colour perception.

Reply to
Gib Bogle

** Oh yeah - human eyes quickly correct for varying ambient lighting conditions, including the colour, so we see colours much the same as in daylight.

OTOH a camera is a dumb animal and sees colour pretty much as it is.

Take a pic of someone standing under a leafy tree and they look greenish.

.... Phil

Reply to
Phil Allison

t

on

r

ore

hey

The P4 phosphor has a radiance peak at 450nm. See for example, Fig. 4 here:

research.opt.indiana.edu/Library/Fry91/Fry1991.pdf

Reply to
spamtrap1888

On reflection ... some of the places where I observed TVs from outside had no street lights. It was quite dark. Hmm.

Reply to
Gib Bogle

"Gib Bogle"

** But all the homes had incandescent lights on inside - so the same thing happens.

.... Phil

Reply to
Phil Allison

Maybe ... I can't remember.

Reply to
Gib Bogle

Maybe they did, I can't remember. But if the TV looks blue in comparison with the incandescent lights from outside, why not from inside too?

Reply to
Gib Bogle

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