In the 1970s, GE devised a method to automatically correct
luminance and chroma imbalances occurring in the broadcast
chain between studio, transmitter, and consumer receiver:


https://books.google.com/books?id=Cg...ence%22&f=true


For whatever reason, by the mid-1990s, the system fell out
of favor, and consumers were once again left to their own resources
as to where their TV picture adjustments should be set.


Considering how modern digital TVs appear as shipped from
manufacturers, and considering just how high a level of
inaccuracy the viewing public are presently unwittingly willing to endure,
could such an "automatic calibration" system, similar to VIR
above, be implemented today?

On 27/04/2015 11:30, wrote:
In the 1970s, GE devised a method to automatically correct
luminance and chroma imbalances occurring in the broadcast
chain between studio, transmitter, and consumer receiver:


https://books.google.com/books?id=Cg...ence%22&f=true


For whatever reason, by the mid-1990s, the system fell out
of favor, and consumers were once again left to their own resources
as to where their TV picture adjustments should be set.


Considering how modern digital TVs appear as shipped from
manufacturers, and considering just how high a level of
inaccuracy the viewing public are presently unwittingly willing to endure,
could such an "automatic calibration" system, similar to VIR
above, be implemented today?


What chance have they got for sorting that out when they can't even get
lip sync right in the UK. Surely the digital set-top pictures should
hold the picture back until audio and video are in sync?

"N_Cook" wrote in message
...
On 27/04/2015 11:30, wrote:
In the 1970s, GE devised a method to automatically correct
luminance and chroma imbalances occurring in the broadcast
chain between studio, transmitter, and consumer receiver:


https://books.google.com/books?id=Cg...ence%22&f=true


For whatever reason, by the mid-1990s, the system fell out
of favor, and consumers were once again left to their own
resources
as to where their TV picture adjustments should be set.


Considering how modern digital TVs appear as shipped from
manufacturers, and considering just how high a level of
inaccuracy the viewing public are presently unwittingly
willing to endure,
could such an "automatic calibration" system, similar to VIR
above, be implemented today?


What chance have they got for sorting that out when they can't
even get lip sync right in the UK. Surely the digital set-top
pictures should hold the picture back until audio and video are
in sync?


A few years ago, a relative of mine bought a Samsung LCD TV along
with a DTH satellite system. The TV's picture controls don't work
when used with the DTH set. The default settings of the set-top
box had contrast and colour waaaay too high and did not remember
user settings. I couldn't find any provision for manually saving
the settings either. Whenever power is turned off and on and even
when changing a channel, one had to adjust the picture settings
all over again. I remember thinking "How can such clever people
(the manufacturers) be so stupid in other things?"

wrote:

Considering how modern digital TVs appear as shipped from
manufacturers, and considering just how high a level of
inaccuracy the viewing public are presently unwittingly willing to endure,
could such an "automatic calibration" system, similar to VIR
above, be implemented today?

I don't think there is a point anymore.

That VIR system was more of a gimmick to me, basically added an indicator
lamp that gave false-security to the owner that "something" was working. My
point is, it only made sure the transmission from studio to the home was in
order, but it didn't know anything about the condition of the set.

If the picture tube was aging and had like a blue tint to it, the VIR did
nothing to help that. If the set wasn't calibrated well, needed convergence,
gray scale tracking, same thing, VIR did nothing.

Remember when that was developed, everything was analog, from the camera
recording in the studio to tape, copying the tape, pumping the signal up and
down from satellite, the franchise tv stations who may of received tape
copies in the mail, to their own equipment, studio and transmitter. Anything
in that chain could alter chroma, phase problems with that, black levels
which changed the brightness to contrast ratios. The VIR was there (not being
altered with all that) to act as a reference.

The problem was, most people never noticed a difference with VIR stations
and non-VIR and like I said, it didn't compensate for out of spec tv's.
Things were not that bad really with most stations having engineers that
mostly did quality control, monitoring the "AIR" signal, live.

With the way things are now, everything is digital, bits-is-bits and except
for dropouts when the error rate is exceeded, I don't think a digital signal
from the studio can be altered all that much, no matter how it's transported
from A to B.

I think what you need to do is explain why you think it's needed? I mean
there are crappy lcd/led tv's and good to excellent ones but like they say,
you can't make a silk purse out of a sows ear.

-bruce

Bruce Esquibel wrote: "I think what you need to do is
explain why you think it's needed? I mean
there are crappy lcd/led tv's and good to excellent
ones but like they say,..."


I believe it's needed(but like VIR can be disabled)
because the vast majority of set owners, since
2000 anyway, don't even know their flat panels
*have* menus, let alone know how to set picture
adjustments or anything else in them for that matter.


I'm a huge advocate *for* accuracy in picture &
sound, but also an opponent of "personal
preference". Personal preference to me is
like visiting the Great Pyramid or EIffel Tower
and wishing they could be colored green, or
pink. They are the colors they are, and those
colors/surface textures should be rendered
accordingly on a well set-up display.


I first calibrated an old CRT with Avia 10 years
ago, and after seeing the results, I never looked
at TV the same way. Now when I see display in
default mode(usually Vivid or Dynamic), or
user preference(Sports mode), i just can't look
at it for more than a few minutes before realizing
something needs to be done! The guy reading
the network news does not wear eye shadow!
(sharpness cranked too high). LOL

formulerede spørgsmålet:
Bruce Esquibel wrote: "I think what you need to do is
explain why you think it's needed? I mean
there are crappy lcd/led tv's and good to excellent
ones but like they say,..."


I believe it's needed(but like VIR can be disabled)
because the vast majority of set owners, since
2000 anyway, don't even know their flat panels
*have* menus, let alone know how to set picture
adjustments or anything else in them for that matter.

How would this work?
Unless the tv have a camera to see the lighting condition, the only
thing it can do is to adjust the contrast, hue, etc to a preset level,
which could just as be done at the factory.

But then again, many sets are probably adjusted to look good in the
shop, not in the living room.

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.

On Monday, April 27, 2015 at 8:21:33 AM UTC-4, Bruce Esquibel wrote:


That VIR system was more of a gimmick to me, basically added an indicator
lamp that gave false-security to the owner that "something" was working. My
point is, it only made sure the transmission from studio to the home was in
order, but it didn't know anything about the condition of the set.


That's true, but the VIR TVs were all solid state, and were amazingly consistent from sample to sample as opposed to 60s TVs which took at least a half hour of dealer prep to get right. Back then, they came out of the box fairly well calibrated and even so, a good portion of them were sold by servicing dealers who would tweak them.

As far as the VIR circuitry, it was gimmicky in nature but was not a gimmick from a technical standpoint. They did indeed work and considering the IC technology of time, were actually amazing. I can't recall though if the customer could add or subtract some chroma to get the VIR adjusted levels more to their liking, but I do recall some customers back then had bizarre ideas of what good color looked like.

I do recall them not being trouble free though, and GE provided a simple way to bypass the VIR module if it crapped.

"That VIR system was more of a gimmick to me,..."

Not really a gimmick. It did work but only adjusted the chroma level and phase. (color and tint) It could have done more, like keep the gain and pedestal (contrast and brightness) right, now that sets had DC restoration. They decided not to do that and I think I understand why. Nowhere in the world did people adjust their TVs like here. Some had the color too high. Alot of them, and I mean quite alot of them had the faces too red with the tint (or hue) control. Those people would say I set the faces too green.

Over in Europe, with a slightly more modern system there was no hue or tint control. The phase errors in NTSC were caused by vulnerability to frequency response errors and a few other things to which PAL for example was immune.

The VIR or VITS (slightly different but very similar) was not intended to set the color on people's TV sets. It was intended for the stations to use. In NYC there was a control room for the major network, let's say NBC. They originated the shows on the network, like the national news and other nationwide programming. The loop went all the way around the country and it was of course degraded by the time it got back. And delayed of course.

But the VITS or VIR was hat told them alot more about the signal quality. It had one line of NTSC color bars, one line of staristep and one line of multiburst. (later, closed captioing was right under it) They could have used the stairstep for ghost cancellation I think but never did. The technology was not cheap enough for consumers. Phillips DID develop a ghost cancelling system and I think the stations did start =sending its specified signal during vertical retrace, but I never saw it in operation and have doubts as to whether even one single unit was sold. But Phillips built TVs had a video in/out loop for it just like a tape monitor on an audio amp. (for a few years only)

On a scope with dual time base you could separate those lines out from the vertical retrace interval and see the actual waveforms. When TVs had a vertical hold control you could roll it down and have a look. Another cool thing that was in there was a signal for the commercials to start.

That was a white rectangle at the upper left of the frame, so far up in the corner that no TV of the time would show it due to overscan and/or not a quite rectangular screen. It was only on network programming, obviously that tells the local stations to cue their local commercials which would be interspersed with the national commercials. I am pretty sure those (imperfect) commercial "zappers" used that signal.

Damn do I have alot of useless information ! All of this is completely obsolete.

"How would this work?
Unless the tv have a camera to see the lighting condition, the only
thing it can do is to adjust the contrast, hue, etc to a preset level,
which could just as be done at the factory. "

A bunch of them actually had light sensors and would adjust to lighting conditions.

Hmm, not sure if I ever saw onee with that AND the VIR system. the only two brands I can think of ith VIR were GE before they got bought by Thompson and Sylvainia, GTE Sylvania, not Phillips. Both of them did have the light sensor in some models but stillnot WITH VIR as far as I can remember.

Hmmm, it's a conspiracy !

wrote:

I believe it's needed(but like VIR can be disabled)
because the vast majority of set owners, since
2000 anyway, don't even know their flat panels
*have* menus, let alone know how to set picture
adjustments or anything else in them for that matter.

Yeah but you are talking about two different things.

What you want (or is more along the lines) is something like the modern day
surround sound receivers where they come with a microphone and some kind of
software in the receiver.

After you install the receiver and hook the speakers up, you plug the mic in
and place it where you usually will be sitting. Then when the receiver is in
the setup mode, it plays different white noise, sweep tones, shifting around
speaker to speaker. Then when it has all the info from the mic, it can set
the EQ and volume levels per channel by itself.

Probably not all that accurate (although the one in my Yamaha did say one
speaker was out-of-phase, and it was internally) but better than having
nothing.

To make the tv generate patterns or color sweeps is probably trivial and
cheap, but what would you use for a camera to feed back to itself? You can't
exactly include a $1000 hd camera with a $400 tv but the idea would be the
same, point the camera at the screen from where you normally sit, let the tv
run the tests, the camera feeds back to the tv and let it adjust itself to
room settings.

It may not even has to be a camera in the conventional sense, just some kind
of optical sensor that can detect white/black and color intensity or
something. As long it know what to expect from the tv (and when), it
probably would come closer than playing around with the menus manually.

Just saying it would have to be more along this line than anything like VIR
being added in.

-bruce

Bruce Esquibel:

The original premise of VIR is that the TV would be aligned
with a luma/chroma/phase/peak signal sent 60x sec from
the station on a specific scan line.


VIR was not something done in the home, with test patterns
and a camera or sensor mounted to the screen. That is called
calibration.


The key phrase here is: "aligned with the station". Of course,
there could be the option, in this glorious digital age, of user
override of certain adjustments, such as the Backlight on
LCD/OLED TVs, to compensate for specific in-room viewing
conditions, day vs night, etc.


But at the very least, the color, hue, and sharpness would
be locked in automatically.


And it would still be up to the user to locate and disable non-
standard eye-candy such as "auto skin tone". "noise reduction",
or "motion sensitive lighting". Basically, all just effects that add
nothing(useful anyway!) to the image.

Efter mange tanker skrev :
Bruce Esquibel:

The original premise of VIR is that the TV would be aligned
with a luma/chroma/phase/peak signal sent 60x sec from
the station on a specific scan line.

This would not be neccessary on european PAL (Phase Alternate
Line),where alternate lines are in opposite phase, cancelling any phase
shift in the chroma signal, only in the US NTSC (Never Twice Same
Colour) system.


The key phrase here is: "aligned with the station". Of course,
there could be the option, in this glorious digital age, of user
override of certain adjustments, such as the Backlight on
LCD/OLED TVs, to compensate for specific in-room viewing
conditions, day vs night, etc.

But at the very least, the color, hue, and sharpness would
be locked in automatically.

This is digital, it is unchanged from mixing console to tv, the only
variable is how the pixels on the screen responds to the signal, so VIR
would not help here. The only thing which needs adjusting is this
response and allowance for lighting conditions in the wieving room.

Leif

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.

Leif:


Sorry if the premise of this thread was not clear. The
primary target of a digital version of VIR is the consumer
end. My whole focus is exposing as many home viewers
as possible to an accurate picture.


The "factory default" settings, such as they are, do
absolutely nothing for home/office lobby/hotel foyer
TV viewing. Digitally transmitted VIR would "reach
inside the consumer set, and automatically adjust the
contrast, brightness, color, hue etc, regardless of
where the consumer or factory adjusted them to,
to match and pass through the station's output
directly to the screen.


Local override of backlight and black level could still
be allowed to compensate for any viewing conditions
from pitch dark to high noon.


VIR would still not apply to auxiliary inputs(VHS, DVD,
Blu Ray, HDMI, etc.).

Den 28-04-2015, skrev :
Leif:


Sorry if the premise of this thread was not clear. The
primary target of a digital version of VIR is the consumer
end. My whole focus is exposing as many home viewers
as possible to an accurate picture.


The "factory default" settings, such as they are, do
absolutely nothing for home/office lobby/hotel foyer
TV viewing. Digitally transmitted VIR would "reach
inside the consumer set, and automatically adjust the
contrast, brightness, color, hue etc, regardless of
where the consumer or factory adjusted them to,
to match and pass through the station's output
directly to the screen.

The analog VIR was to override transmission errors and ensure that the
hue the station sent was the same as what the receiver got, regardless
of distance, atmospheric conditions etc.

You still had to calibrate your tv-set, but theoretically just once,
not every time the disturbances changed.

In the digital age, when the mixer sends 75% green, 20% red, 15% blue,
the tv gets the same.

Even if your "Digital VIR" tries to set every receiver to 65%
brightness, 50% contrast, 68% colour saturation, you have no way of
being sure the pictures are looking the same on Sony, Samsung or
Chevrolet TV-sets, new or old, plasma, LCD, LED etc.

Unless you have an equally calibrated sensor/camera at the VIR's
disposal.

Leif

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.

Leif: Read the article again: https://books.google.com/books?id=Cg...ence%22&f=true


You're not getting what VIR *also* did.

It also internally adjusted the picture controls to
proper levels, regardless of how the kid screwed
up the knobs on dad's new 25" console.

Den 28-04-2015, skrev :
Leif: Read the article again:
https://books.google.com/books?id=Cg...ence%22&f=true


You're not getting what VIR *also* did.

It also internally adjusted the picture controls to
proper levels, regardless of how the kid screwed
up the knobs on dad's new 25" console.

So it is basically a "reset to preset values"

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.

On Wednesday, April 29, 2015 at 1:30:03 AM UTC-4, Leif Neland wrote:

So it is basically a "reset to preset values"


When the GE VIR equipped TV picked up the VIR signal, it would set it's chroma level and phase to what the broadcaster set it for, not any preset value. The theory is that it didn't matter what happened to level and phase during transmission, retransmission and final reception at the TV. The VIR signal told the TV what level and phase to set the chroma to.

It was defeatable with a switch. I remember one station where the color went all green on every VIR TV I saw for a whole summer.

John-Del skrev:
On Wednesday, April 29, 2015 at 1:30:03 AM UTC-4, Leif Neland wrote:

So it is basically a "reset to preset values"


When the GE VIR equipped TV picked up the VIR signal, it would set it's
chroma level and phase to what the broadcaster set it for, not any preset
value. The theory is that it didn't matter what happened to level and phase
during transmission, retransmission and final reception at the TV. The VIR
signal told the TV what level and phase to set the chroma to.

It was defeatable with a switch. I remember one station where the color went
all green on every VIR TV I saw for a whole summer.

Again, when digital, the level and the phase of the chroma at the TV
(if that even makes sense in the digtal world) is always the same as
the broadcaster sends.

You can't set all receivers to the same colour, saturation and hue
values, because TV's varies, both between models and manufactures, but
also ageing.

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.

Thanks John-Del for clarifying that. That all-green situation sounds
like PEBCAC.

forklarede den 28-04-2015:


That was a white rectangle at the upper left of the frame, so far up in the
corner that no TV of the time would show it due to overscan and/or not a
quite rectangular screen. It was only on network programming, obviously that
tells the local stations to cue their local commercials which would be
interspersed with the national commercials. I am pretty sure those
(imperfect) commercial "zappers" used that signal.

Here, there is station logo when the "real" program is send, the
station logo is turned off during commercials.

I really wish my PVR could use this for pausing recording or for
skipping during playback.

Leif

--
https://www.paradiss.dk
Ting til konen eller kæresten.
Eller begge.

Leif:

We get it, we get it, we get it! Digital transmission stays
intact from transmitter to receiver. Fine.


But that's NOT what we're talking about, not me at least.


Folks, please let Leif believe what he wants to, and not
argue with him.


Interesting thing I'd like to point out: I posted this topic also to
rec.video and alt.video, and guess what: NO traffic there. That's like
a Pacquiao V Mayweather thread getting no comments on a
BOXING newsgroup. smh...

On Mon, 27 Apr 2015, wrote:

"That VIR system was more of a gimmick to me,..."

Not really a gimmick. It did work but only adjusted the chroma level and phase. (color and tint) It could have done more, like keep the gain and pedestal (contrast and brightness) right, now that sets had DC restoration. They decided not to do that and I think I understand why. Nowhere in the world did people adjust their TVs like here. Some had the color too high. Alot of them, and I mean quite alot of them had the faces too red with the tint (or hue) control. Those people would say I set the faces too green.

Over in Europe, with a slightly more modern system there was no hue or tint control. The phase errors in NTSC were caused by vulnerability to frequency response errors and a few other things to which PAL for example was immune.

The VIR or VITS (slightly different but very similar) was not intended to set the color on people's TV sets. It was intended for the stations to use. In NYC there was a control room for the major network, let's say NBC. They originated the shows on the network, like the national news and other nationwide programming. The loop went all the way around the country and it was of course degraded by the time it got back. And delayed of course.

But the VITS or VIR was hat told them alot more about the signal quality. It had one line of NTSC color bars, one line of staristep and one line of multiburst. (later, closed captioing was right under it) They could have used the stairstep for ghost cancellation I think but never did. The technology was not cheap enough for consumers. Phillips DID develop a ghost cancelling system and I think the stations did start =sending its specified signal during vertical retrace, but I never saw it in operation and have doubts as to whether even one single unit was sold. But Phillips built TVs had a video in/out loop for it just like a tape monitor on an audio amp. (for a few years only)

On a scope with dual time base you could separate those lines out from
the vertical retrace interval and see the actual waveforms. When TVs had
a vertical hold control you could roll it down and have a look. Another
cool thing that was in there was a signal for the commercials to start.

That was a white rectangle at the upper left of the frame, so far up in
the corner that no TV of the time would show it due to overscan and/or
not a quite rectangular screen. It was only on network programming,
obviously that tells the local stations to cue their local commercials
which would be interspersed with the national commercials. I am pretty
sure those (imperfect) commercial "zappers" used that signal.

I was using a Commodore monitor with a VCR as a tv set in the until I got
an LCD DTV set in 2011. And one of the Commodore monitors I used
displayed that white block very cleanly. I didn't know about it, but soon
realized it was an indicator of a commercial, really useful. But I think
I only noticed it on one station, or maybe "not all stations". And then I
had to change the monitor to another Commodore, and it no longer showed
that corner with the white block.

Michael

Just for kicks, I did a search for "calibration" on the
newsgroup rec.video. Now answer me this:

WHY hasn't the subject of display calibration been
brought up since the year 2000?!

wrote:
Just for kicks, I did a search for "calibration" on the
newsgroup rec.video. Now answer me this:

WHY hasn't the subject of display calibration been
brought up since the year 2000?!


Hmmm, because that is about the time CRT's started to get phased out?

I mean I know anything today can be tweaked to be "a bit better" but it's
not going to be anything as dramatic as the CRT days.

What was the name of that group, SFS or FSS something, they had like classes
to do complete calibration on projectors, tv's and other display devices
back in the 1990's. Seemed to fade away about the same time from being
relevant. I seen them mentioned recently, guess they are still plugging away
with front projection systems.

This thread is getting silly anyway, people seem to be in search of an
answer to a problem that doesn't really matter anymore. I can see
differences in technologies, plasma vs. lcd vs. led vs. oled but within each
family, not so much to matter, to me anyways.

-bruce

Bruce Esquibel:

The name of the group, in my reply just
before yours, is REC.VIDEO.


The problem still exists today, just from
a different end: The consumer's display.


Due to consumers either not knowing or
just not caring, their modern digital/HD
TVs are left in, ironically, the WORST
modes ever contrived for a TV in the
history of television. This may be called
'Vivid' or 'Dynamic', by different manu-
facturers.


And many set owners don't even know,
or care, that that a menu even EXISTS
for them to get a more accurate picture
by just turning off a few things, and
adjusting a few others. Plus, their TV
will consume less energy and last much
longer.


But all that doesn't matter, Bruce, does it?
Nor does the fact that an Imaging Science
Foundation exists, along with standards
set long ago by both them and the SMPTE.


They must just be out of their mind, stark-
raving CUCKOO for all some of us care.

On Tuesday, April 28, 2015 at 1:03:40 PM UTC-7, wrote:
Leif: Read the article again: https://books.google.com/books?id=Cg...ence%22&f=true


You're not getting what VIR *also* did.

It also internally adjusted the picture controls to
proper levels, regardless of how the kid screwed
up the knobs on dad's new 25" console.

That's all well and good but VIR applied to analog TV broadcasting which was turned off - permanently (YEA) - in June 2009. VIR had a preset amplitude and phase (hue) subcarrier riding on a defined amplitude pedestal to set brightness, contrast hue and saturation and nothing more. Keep in mind that this does NOTHING about bias and gain on the display (back then CRT) device.. How your TV was aligned was up to you and your repair tech.

That's ALL that VIR could and did do.

G²

On Tuesday, May 5, 2015 at 5:39:42 PM UTC-4, wrote:
VIR had a preset amplitude and phase (hue) subcarrier riding on a defined amplitude pedestal

It was a bit more than that. It wasn't a preset value; the broadcaster would set the saturation and phase, even changing it to compensate for different film systems or video tape variances from program to program.


....riding on a defined amplitude pedestal to set brightness, contrast hue and saturation and nothing more.

My recollection is that it did not adjust brightness or picture (contrast)

Keep in mind that this does NOTHING about bias and gain on the display (back then CRT) device. How your TV was aligned was up to you and your repair tech.

That's true, but grey scale and black level were amazingly close from sample to sample. I would say that the grey scale adjustment of the average GE from that era was quite close to perfect. The Japanese TVs of that era were shipped above 9000 k.

6:53 PMJohn-Del wrote:
"That's true, but grey scale and black level were amazingly close from sample to sample.
I would say that the grey scale adjustment of the average GE from that era was quite close to
perfect. The Japanese TVs of that era were shipped above 9000 k. "


Were sets really that close to accurate(6500) 30-40 years ago? And does that suggest
that the trend toward bluer-brighter-oversharpened TVs is relatively new - post-millennium?


If that was so, then my notion that calibration and accurate adjustment matter more than
number of lines or pixels is right on. And I wish I had one of those old knob-clicker-tuners
sitting around the house - perhaps underneath my LED smart TV as a base for it!


Of course, calibration is a taboo subject on these newsgroups, despite the factory settings
of modern flat screens meaning that calibration is needed NOW more than ever in the history
of television!

See? Soon as I mention the "c-" word everyone runs under a table
nearby or folds up like a two-dollar suitcase.

In article ,
wrote:

6:53 PMJohn-Del wrote:
"That's true, but grey scale and black level were amazingly close from sample
to sample.
I would say that the grey scale adjustment of the average GE from that era
was quite close to
perfect. The Japanese TVs of that era were shipped above 9000 k. "


Were sets really that close to accurate(6500) 30-40 years ago? And does that
suggest
that the trend toward bluer-brighter-oversharpened TVs is relatively new -
post-millennium?

Bluer, or just closer to white than you're used to?

Isaac

On Tuesday, May 5, 2015 at 3:53:28 PM UTC-7, John-Del wrote:
On Tuesday, May 5, 2015 at 5:39:42 PM UTC-4, wrote:
VIR had a preset amplitude and phase (hue) subcarrier riding on a defined amplitude pedestal

It was a bit more than that. It wasn't a preset value; the broadcaster would set the saturation and phase, even changing it to compensate for different film systems or video tape variances from program to program.


....riding on a defined amplitude pedestal to set brightness, contrast hue and saturation and nothing more.

My recollection is that it did not adjust brightness or picture (contrast)

Keep in mind that this does NOTHING about bias and gain on the display (back then CRT) device. How your TV was aligned was up to you and your repair tech.

That's true, but grey scale and black level were amazingly close from sample to sample. I would say that the grey scale adjustment of the average GE from that era was quite close to perfect. The Japanese TVs of that era were shipped above 9000 k.



From Wikipedia. I know this is correct because I used to maintain this equipment at the CBS affiliate in Madison WI, WISC TV 3.

VIR (or Vertical interval reference), widely adopted in the 1980s, attempts to correct some of the color problems with NTSC video by adding studio-inserted reference data for luminance and chrominance levels on line 19.[25] Suitably equipped television sets could then employ these data in order to adjust the display to a closer match of the original studio image. The actual VIR signal contains three sections, the first having 70 percent luminance and the same chrominance as the color burst signal, and the other two having 50 percent and 7.5 percent luminance respectively.[26]

The signal was NOT altered by the local broadcaster. It was intended to correct black level, gain, phase (hue) and saturation errors that may occur during transmission. In Channel 3s case, a Tektronix 1440 (?) video corrector processed the incoming CBS network feed to maintain those parameters. At the time network came via terrestrial microwave and was extremely consistent even without the corrector.

IF your TV referenced VIR, all it did was those 4 parameters. Any bias (black level) and gain adjustments AFTER the VIR processing may or may not be calibrated correctly. What it DID ensure was that it would be consistent. That's all.

G²

isw wrote:

"Bluer, or just closer to white than you're used to?

Isaac"


Closer to white than I'm used to? White is not
supposed to be bluish. Today's TVs ship to retailers
with the color temp closer to that Japanese standard
mentioned a couple replies back(9,000K), which
renders material produced at 5400(old B&W movies)
or 6,500K(broadcast) most inaccurately - bluish.


Question: Have you seen an accurate or calibrated
accurate TV? Or one with at least the Basic-Five
controls set correctly with medium or warm color
temp setting?

On Tue, 5 May 2015 15:53:24 -0700 (PDT), John-Del
wrote:

On Tuesday, May 5, 2015 at 5:39:42 PM UTC-4, wrote:
VIR had a preset amplitude and phase (hue) subcarrier riding on a defined amplitude pedestal

It was a bit more than that. It wasn't a preset value; the broadcaster would set the saturation and phase, even changing it to compensate for different film systems or video tape variances from program to program.


....riding on a defined amplitude pedestal to set brightness, contrast hue and saturation and nothing more.

My recollection is that it did not adjust brightness or picture (contrast)

Keep in mind that this does NOTHING about bias and gain on the display (back then CRT) device. How your TV was aligned was up to you and your repair tech.

That's true, but grey scale and black level were amazingly close from sample to sample. I would say that the grey scale adjustment of the average GE from that era was quite close to perfect. The Japanese TVs of that era were shipped above 9000 k.


You are correct that VIR only set saturation and hue. Those PM
chassis GEs were awesome. It is a shame they abandomed them when they
boughrt RCA. GE was in the process of selling an oil based consumer
projection tv when the division was folded.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

Chuck: "oil based projection tv"


????

On Wed, 06 May 2015 08:16:36 -0500, Chuck wrote:

On Tue, 5 May 2015 15:53:24 -0700 (PDT), John-Del
wrote:

On Tuesday, May 5, 2015 at 5:39:42 PM UTC-4, wrote:
VIR had a preset amplitude and phase (hue) subcarrier riding on a defined amplitude pedestal

It was a bit more than that. It wasn't a preset value; the broadcaster would set the saturation and phase, even changing it to compensate for different film systems or video tape variances from program to program.


....riding on a defined amplitude pedestal to set brightness, contrast hue and saturation and nothing more.

My recollection is that it did not adjust brightness or picture (contrast)

Keep in mind that this does NOTHING about bias and gain on the display (back then CRT) device. How your TV was aligned was up to you and your repair tech.

That's true, but grey scale and black level were amazingly close from sample to sample. I would say that the grey scale adjustment of the average GE from that era was quite close to perfect. The Japanese TVs of that era were shipped above 9000 k.


You are correct that VIR only set saturation and hue. Those PM
chassis GEs were awesome. It is a shame they abandomed them when they
boughrt RCA. GE was in the process of selling an oil based consumer
projection tv when the division was folded.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com


I shouldn't have said that the VIR signal didn't have a reference for
luminance adjustment. I believe the PM chassis VIR circuitry didn't
use these values.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

On Wed, 6 May 2015 06:21:37 -0700 (PDT), wrote:

Chuck: "oil based projection tv"


????
Look up professional 1980s GE projection televisions for closed
circuit events like fights on Google . They were oil emulsion based.
GE put out a sheet of products that were going to be released in the
next year and that set was one of them. The division folded a month
later.

---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com

Chuck:

Some kind of lubricant..

I know what oil-based paintings are, but
oil-based TV? That one through me, lol!

On Wednesday, May 6, 2015 at 11:00:27 AM UTC-4, wrote:


I know what oil-based paintings are, but
oil-based TV?


Refresh rate must have sucked.... [rimshot]


Well, it's not April 1st so I looked and:

http://www.earlytelevision.org/eidophor.html

On Tuesday, May 5, 2015 at 7:35:27 PM UTC-4, wrote:



Were sets really that close to accurate(6500) 30-40 years ago? And does that suggest
that the trend toward bluer-brighter-oversharpened TVs is relatively new - post-millennium?

In the tube era, TVs came out of the box a mess. I was just a kid but learned to converge and grey scale RCAs and Zeniths (Zeniths were better prepped out of the box) in a hurry before delivery. Delta tube convergence was hit or miss, but RCA's adjustments had less interaction than anyone.

Once the solid state XL-100 hit the market in 1971, things changed. These came out of the box almost perfect and the Zeniths and GEs showed big improvements as well. The Sonys and Panasonics were consistent, but consistently blue.

RCA always specified 6500 Kelvin for their grey scale.

"I shouldn't have said that the VIR signal didn't have a reference for
luminance adjustment. "

It did. As I said there was a line of the NTSC color baar standard, stairstep and multiburst.

Though the VIR equipped sets only used two bars of the NTSC color bars, it could have done alot more. There was just no money in it. I don't recall exactly how it worked but it only adjusted the phase to make two of the bars the same, or at a specified differential level. And there were settings fo it, it is just they were referenced to those levels.

Rewalistically, had they wanted to they could have compensated for bandwidth problems, maybe even multipath using the stairstep and/or the mutiburst. But again, there was no money in it.

Broadcasters may well have made adjustments manually, it doesn't matter. The thing is it was adjusted to that test signal. The video is the video, if it looks ****ty it is not our fault, that is how it is. Our equipment is fine.

the real problem is that this has become much ado about nothing. when I was young we only had a few TV stations. I mean some people had UHF convertors.. On Friday night we had to look at the TV guide that came with the local newspaper and decide what to watch. Choosing from a whopping five channels in the days of the new UHF band.

Now there are 300 channels and the best button is "power off".