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...
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?!
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 snipped-for-privacy@ripco.com
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.
That's all well and good but VIR applied to analog TV broadcasting which wa s turned off - permanently (YEA) - in June 2009. VIR had a preset amplitude and phase (hue) subcarrier riding on a defined amplitude pedestal to set b rightness, 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.
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.
My recollection is that it did not adjust brightness or picture (contrast)
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.
Bluer, or just closer to white than you're used to?
Isaac
ned amplitude pedestal
ould set the saturation and phase, even changing it to compensate for diffe rent film systems or video tape variances from program to program.
hue and saturation and nothing more.
)y (back then CRT) device. How your TV was aligned was up to you and your re pair tech.
ple to sample. I would say that the grey scale adjustment of the average G E from that era was quite close to perfect. The Japanese TVs of that era w ere shipped above 9000 k.
From Wikipedia. I know this is correct because I used to maintain this equi pment 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-ins erted reference data for luminance and chrominance levels on line 19.[25] S uitably equipped television sets could then employ these data in order to a djust the display to a closer match of the original studio image. The actua l VIR signal contains three sections, the first having 70 percent luminance and the same chrominance as the color burst signal, and the other two havi ng 50 percent and 7.5 percent luminance respectively.[26]
The signal was NOT altered by the local broadcaster. It was intended to cor rect black level, gain, phase (hue) and saturation errors that may occur du ring transmission. In Channel 3s case, a Tektronix 1440 (?) video corrector processed the incoming CBS network feed to maintain those parameters. At t he 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 (bla ck level) and gain adjustments AFTER the VIR processing may or may not be c alibrated correctly. What it DID ensure was that it would be consistent. Th at's all.
"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?
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"
????
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
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!
Refresh rate must have sucked.... [rimshot]
Well, it's not April 1st so I looked and:
that suggest
- post-millennium?
In the tube era, TVs came out of the box a mess. I was just a kid but lear ned to converge and grey scale RCAs and Zeniths (Zeniths were better preppe d out of the box) in a hurry before delivery. Delta tube convergence was h it 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 impro vements as well. The Sonys and Panasonics were consistent, but consistentl y blue.
RCA always specified 6500 Kelvin for their grey scale.
luminance adjustment. "
It did. As I said there was a line of the NTSC color baar standard, stairst ep 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 ex actly 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 bandwidt h 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. Th e thing is it was adjusted to that test signal. The video is the video, if it looks shitty it is not our fault, that is how it is. Our equipment is fi ne.
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 n ewspaper and decide what to watch. Choosing from a whopping five channels i n the days of the new UHF band.
Now there are 300 channels and the best button is "power off".
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.