You turn it one way, it makes the people green. You turn it the other, it makes them purple. So I usually keep it always on the same middle position. But it must be there for some purpose. What exactly is the “tint” knob for on televisions?
It’s for adjusting the tint of the picture, as you found out. If the image is too red, you turn the knob toward green and vice versa. I remember when I was a kid that the tint needed to be adjusted on some sets. My current telly is about a dozen years old, and its tint has never needed to be adjusted. Basically, having a knob allows the consumer to adjust the colour himself instead of having to take the telly into a repair shop.
You’ll notice that your computer monitor has colour controls on it as well. I put up a page of paint chips for the Willys CJ2A. I matched the colours on my monitor with the original 1940s chip page. When I changed my monitor, the colours no longer matched. Televisions probably have similar variances as monitors, but I suspect they are more closely matched than monitors.
You’ll occasionally see colour bars on TVs/DVDs/Videos. If you adjust the tint on your TV so that the colour bars are “true”, then your images will be correctly balanced. That’s what the colour bars are for.
When a tv signal is assembled, there are many parts which have to be timed relative to one another.
Colour information, also called chrominance, is carried, along with sound, picture information - called luminace - and also frame and line timing information and some systems also carry a certain amount of digital data.
Referance signals are encoded within the total signal which is now called a composite signal.
Those referance signals are then used to correct any errors caused by long distance transmission.
Long distance transmission has the effect of changing the timing of one part of a signal relative to another part, if you like you could say it can cramp the higher and lower ranges of the signal, or it can smear them apart.
In much of Europe we use PAL tv, which has a way of trading the colour strength off against colour accuracy, so our tv pictures here can sometimes look a bit ‘washed out’ compared to the US system, but at least everything ends up the correct colour. The more smeared around the signal gets, the more washed out the colur becomes.
The system was first used in Germany and all the patents were held by European manufacturers, or the rights to use the technology were traded to EU manufacturers, it was a way to try keep the Japanese manufacturers out as transmissions standards had to be such to allow the system to work to the exclusion of others, and broadcast equipment is also a lucrative market.
The US employs another tv standard called NTSC, which does not have this method of automatic colour control, thus is a tv signal is smeared by transmission, there is no obvious means of unsmearing it.
The tint control is used in US tv systems to change a referance point that the colour decoder uses (effectively unsmearing the colour signal)and this then allows a correct colour to be displayed.
In Europe the Japanese had to find a way around the immediate problem of not having the rights to use PAL technology in its original specification, so they used the tint control as a temporary workaround, but being ingenious folk, the Japanse noticed that instead of correcting colour line by line, it could be done in a similar way using frame by frame and this got around the patents. This method is not quite as accurate, but it was obvious to the patent holders that it was only a matter of time before SONY et al found a way around this so the PAL technology was licensed to them - might as well get some revenue out of the patent as get nothing at all.
The US system does have the advantage that you get a much more detailed picture and when the colour is right US tv does look better - can’t say the same for the content.
TV engineers have their own versions of the tv standards acronyms,
PAL - Picture always lousy.
NTSC - Never twice the same colour.
…as for the French, well they do their own thing ,as usual, with their SECAM system, not that anyone cares.
Would that be
Surrender, Eat Cheese And Moan? 