TV Picture: What Does "Calibration" Mean???

TV Picture: What Does "Calibration" Mean???

Calibration. To calibrate.

With regards to TV sets - of any type - I suspect two things have stood in the way of this process: #1. Most set owners and folks in general, outside of the scientific community, don't know what the dang word even means! And #2. Modern digital TVs are so "good" most people think they don't even need calibration.

Succinctly, calibration means to align something to a given standard, or set of standards. These standards may be physical, electrical, chemical, or in the case of image reproduction, a certain range of color and brightness when standardized patterns are displayed on a TV.

========== The way I have recently started to explain what I do to TVs to the average person is to draw a basic shape on a piece of paper, I.E. a triangle. To the right of that I draw an arrow, then a rectangular box, another arrow, and a blank space.

I then show this to the person, explaining that the triangle is the subject on TV, and the box is their TV set. I then ask them what should they see to the right of all that, after it comes out of their TV set. They answer, "a triangle"?

So I draw a circle! (or, a distorted triangle)

The person looks at me, "what?"

I tell them, without calibration, this is what your TV does to the image of subjects transmitted to it, via inaccurate color, off tint, or too bright or incorrect contrast. Your TV may wow you out of the box, but that factory setting was intended to SELL IT to you, not for long-term TV or movie viewing, or game playing. Plus, it may shorten the set's life.

I then explain the two types of calibration: Basic(brightness, contrast, sharpness, color, tint - the basic user controls), and, advanced(Basic, plus internal color temperature and grayscale alignment.). I then explain that most reputable brands of TVs today(Sony, JVC, Samsung, Pioneer) will deliver an accurate picture with just the basic controls properly set. Cheapo brands(Daewoo, Insignia), or older CRT(tube) TVs might need more advanced additional adjustments to get them in line.

If they ask me what all this will do, I tell them: You will see, if not exactly, an image much closer to what the producer or tv control room engineers see when they make a TV show or a movie. Plus, the image will be far less stressful to the eye, and you might even save energy! ==========

This usually sells them, instead of just asking them, would you like your TV "calibrated"?

Calibration is a big, nerdy, multi-syllable word that few understand, and perhaps shouldn't even be used to describe the process of aligning a display and making it transparent to whatever is shown on it.

No WONDER "display calibration" or "tv calibration" has fallen out of favor!

Waiting for the crickets ....

snipped-for-privacy@gmail.com - Switch accounts - Desktop

Well that's all fine and good, but why did you use the form of a question i n the title ?

Anyway, there is a disk out there called "Video Essentials" which is suppos edly a great aid in doing that. However, for an accurate greyscale you need something to which to compare. For video cameras they had what were called lightboxes which supposedly had a specific color temperature. With a monit or, maybe you can compare to a high brightness piece of paper lit by a lamp with a specific color temperature. Or perhaps sunlight.

Though things can run off still, it is nowhere near as bad as CRTs were. If they weren't burned in enough after cathode activation they would drift, a nd later those miniature cathodes got hotter with increased beam current an d drifted, necessitating AKB. (Auto Kine Balance) And then there is converg ence and purity. The Earth's magnetic field affected the purity quite a bit , and convergence to a lesser degree, except on projection TVs.

The LCD TVs do not really have these problems, they are going to inherently be more accurate out of the box. Same with plasmas but the phosphors in a plasma can weaken with age like any other phosphor. Someone told me the gas in them wears out, and that reduces color temperature. I do not believe it , that should affect all colors equally. I think the blue phosphor wears ou t first. Blue phosphors are the least efficient and therefore will get more drive.

While there are no cathodes, the phosphor does still burn in and weaken wit h heavy use.

There is no convergence or purity adjustment on plasma or LCD (which includ es what they call LED now). Greyscale and color demodulation, are all there is, and with other than NTSC (composite or SVHS) there is no color demodul ation either.

snipped-for-privacy@gmail.com wrote: "Well that's all fine and good, but why did you use the form of a question in the title?"

Because it seems in the last 10 years calibration, or at least the very concept of it, is becoming marginalized, less relevant. The occurrence of the word "calibration" has dropped significantly since the early 2000s according to searches I conducted in usenet groups related to video technology and production.

I sincerely want to share my calibration experiences with others because I'm so excited by what it has done for my TV and video viewing experience. My problem is adjusting my "elevator speech" so that the common man(woman) 'get' what calibration does for their equipment and their viewing.

I've worked in broadcast and post production since 1976 and calibrated many monitors, some used for THX film transfers and verified by their tech. Cal ibration was mandatory with CRT monitors and on a regular basis. The new TV s are amazingly consistent and I find no desire and certainly no need to 't weak' them. In fact, unless you're very qualified I would not allow you to touch my TV.

snipped-for-privacy@yahoo.com wrote: " The new TVs are amazingly consistent and I find no desire and certainly no need to 'tweak' them. In fact, unless you're very qualified I would not allow you to touch my TV.

So if I understand you correctly, If you were to buy a brand new flat panel set, connect it all up and start watching it, you would leave the user menu settings all in their factory positions?

On Wednesday, October 21, 2015 at 8:13:42 AM UTC-4, snipped-for-privacy@gmail.com wro te:

That would depend. We have a Panasonic Plasma TV - the factory settings are *very* bright and the color mix verges on the cartoonish. "Calibrating" in that case allows the user to set the color range, average brightness and s imilar parameters to a more reasonable setting. One can purchase a 'kit' to help with this, and/or use other means to get the colors true. Once done, as otherwise noted, the system seems to remain remarkably stable, even thro ugh power-failures.

That would be my take on the use of that term-of-art for our particular uni t.

Peter Wieck Melrose Park, PA

snipped-for-privacy@aol.com wrote: "- show quoted text -

That would depend. We have a Panasonic Plasma TV - the factory settings are *very* bright and the color mix verges on the cartoonish. "

So you have observed, and agree, that factory default settings on consumer TVs such as your Panasonic and on my Samsung LED are not ideal for extended viewing.

"Calibrating" in that case allows the user to set the color range, average brightness and similar parameters to a more reasonable setting. One can pur chase a 'kit' to help with this, and/or use other means to get the colors t rue. Once done, as otherwise noted, the system seems to remain remarkably s table, even through power-failures. "

And you agree with calibration in your particular case. I did notice that you seem to think that calibration is some- thing that must be done periodically(every year or two for example).

That may have applied in the case of CRT-based TVs or projectors, yes. But not with modern digital flat technology - UNLESS - you change one of your input sources, or upgrade, I.E. from a standard DVD to a Blu-Ray deck. You then recalibrate that input for that device. I tell all of my customers this: that their calibrated settings should not drift for at least a decade. :)

"That would be my take on the use of that term-of-art for our particular un it. "

Peter Wieck Melrose Park, PA "

Not sure what you mean by "term of art". Please elaborate.

On Thursday, October 22, 2015 at 9:29:41 AM UTC-4, snipped-for-privacy@gmail.com wrot e:

No, I stated that the settings, once done, were remarkably stable, even thr ough power-failures. I did have to re-calibrate after a 6-day failure (Hurr icane Sandy), but not for failures as long as several hours.

I have not experienced that need - we switched about 2 years ago from a bas ic DVD player to a compatible, self-upgrading blue-ray DVD with no visible need to re-calibrate - and the software with the kit verified this.

unit. "

Term-of-Art: A word, combination of words or phrase specific to one thing t hat is used outside of its common definition. To me the term "calibrate" is specific to measuring devices, meters, tube testers, signal generators, ro tameters, gauges and so forth that are set to a specific standard such that measurements from them can be trusted. I would not generally consider arbi trary settings based, in part, on taste rather than independent standards, would be any sort of 'calibration'. At least, again, as I understand and wo uld normally use the term. There are those that prefer bright settings and cartoonish colors. De gustibus et coloribus non est disputandum. Quidquid l atine dictum sit, altum videtur.

Peter Wieck Melrose Park, PA

"me the term "calibrate" is specific to measuring devices, meters, tube testers, signal generators, rotameters, gauges and so forth that are set to a specific standard."

Likewise! DVD test patterns also count, as long as one follows instructions on what to look for when the specific control(brightness, contrast) is adjusted optimally.

I still sense a lot of skepticism in your responses regarding display ALIGNMENT - there, I just found a new name for it that makes sense! :)

On Wednesday, October 21, 2015 at 9:37:13 PM UTC-7, snipped-for-privacy@yahoo.com wrote :

ny monitors, some used for THX film transfers and verified by their tech. C alibration was mandatory with CRT monitors and on a regular basis. The new TVs are amazingly consistent and I find no desire and certainly no need to 'tweak' them. In fact, unless you're very qualified I would not allow you t o touch my TV.

Generally, there's no calibration in an LCD TV that requires touching. Dig ital signal, not affected by movable magnets or variable resistors. If you use your TV for a computer monitor, though, and have a color printe r: you ought to calibrate the video card or the printer driver so that the color prints produce the same colors as the screen display. Getting the correspondence right is important for artistic uses, and requires (1) controlling reflected light off the screen (2) getting as much color gamut and contrast on the screen as on the paper (not easy, might require special paper) (3) controlling the illumination light when viewing printed material (4) adjusting R, G, B zero points (5) adjusting R, G, B brightnesses (6) adjusting for any nonlinearity (usually called 'gamma correction') for R, G, B (7) readjusting from time to time, as papers, inks, phosphors may age.

It can be hard to find and rectify any adjustments. Or, it can be easy - A pple made a ColorSync monitor with internal light sensors that did recalibration in a f ew seconds if you pressed the front-panel button).

On Thursday, October 22, 2015 at 2:58:02 PM UTC-4, snipped-for-privacy@gmail.com wrot e:

esters, signal generators, rotameters, gauges and so forth that are set to a specific standard."

Mpffff..... Here we go again....

Alignment: My primary hobby is vintage radio restoration and repair, so "al ignment" is a very specific term. Shifting that term from rF to Visual alig nment is not a stretch, just not what leaped to mind when I read your assig nment of this term to that process. Telescope people call it "collimation", musicians call it "tuning" but they are all forms of aligning some sort of information for greater accuracy/clarity.

Peter Wieck Melrose Park, PA

On Thursday, October 22, 2015 at 1:24:35 AM UTC-7, snipped-for-privacy@gmail.com wrot e:

No. That looked bad because it was in 'store demo' mode. I don't consider t he 'user adjustments' namely brightness, contrast, saturation (color), back light and sharpness to fall into the 'calibration' category. Calibration t o me involves individual RGB gain, lift and gamma. These were finicky with CRTs but don't need much if any tweaking with LED lit LCD sets.

whit3rd wrote: "Generally, there's no calibration in an LCD TV that requires touching. Digital signal, not affected by movable magnets or variable resistors. "

So I will ask you the same question: If you bought and unboxed a brand new flat panel TV for your home, would you leave the user and semi-advanced settings in their factory mode? Have you actually seen a TV(any TV, CRT, Plasma, LED, etc) in its factory defaults?

Again, I'm talking about the SETTINGS, not the broadcast or cable signal fed into the back of it. And no, for the purposes of this dis- cussion, there is no concern of "drift" because we are in the micro- circuit digital realm.

Your silence on this subject speaks volumes. Out of the box, a new con- sumer grade TV is like staring at the midday sun for a half-hour to an hour.

It is typically set to "Vivid" or "Dynamic" mode, which is useful only for display in a retail sales floor environment. Contrast, color and sharpness are cranked, color temperature is skewed to 10,000+Kelvin - ultra blue, and every so-called "enhancer" under advanced settings is checked(skin tone enhancer, black level enhancer, digital noise re- duction, etc.) Backlight(if it's a LED or LCD) is all the way up, etc.

Just taking it out of Vivid, and turning off all that CRAP in the advance menu gets you from some vague location in the South Bronx INTO Yankee Stadium, in terms of accuracy! The professional calibration we discussed here will take you from a seat somewhere in the right- field upper deck right onto home plate.

And there are no "personal preferences" when it comes to picture settings - only one right combination of basic and advanced controls, and 1,000 possible WRONG combinations.

it's your choice: Stare at the sun every night during the 6 o'clock news, or see what the host and the world through the cameras really looks like.

I'm pretty sure it's the other way around -- any decent screen will have a much broader gamut than any subtractive color process (i.e. any sort of image printed on paper). Same with contrast ratio -- the screen wins by an order of magnitude or better.

Isaac

The problem I see with most LCDs is the color temp due to the LED backlighting. Everything is way too cold (blue). Except for that, just peek in a bar with multiple TVs, they're not perfectly matched, but far closer than in the days of CRTs or plasma stuff. There's no phosphors or electron guns to weaken at different rates.

The drift (in everything) in the plasma airport arrival/departure screens was pretty amazing too, even if you cut some slack for those displays having been used in the worst possible conditions.

The problem I see with most LCDs is the color temp due to the LED backlighting. Everything is way too cold (blue). Except for that, just peek in a bar with multiple TVs, they're not perfectly matched, but far closer than in the days of CRTs or plasma stuff. There's no phosphors or electron guns to weaken at different rates.

The drift (in everything) in the plasma airport arrival/departure screens was pretty amazing too, even if you cut some slack for those displays having been used in the worst possible conditions. "

Cyndrome: The reason you are seeing those "way too cold" color temperatures is because in the advance settings the highest/bluest color temperature is set by default!

As for the creature cantina scene - of course the TVs in there are not matched: different mfgs have different factory default settings; but what those settings do have in common is: they were selected to make their product stand out on a sales floor - NOT to be watched for any appreciable length of time.

Bet you a five-legged horse that if even just the user controls(color temp set to neutral instead of high, backlight on LEDs set in half, and the bright, contrast, color, sharpness all set via test DVD) you'd be hard pressed to see any difference between sets at opposite ends of the bar - assuming they are all tuned to the same game, as they likely all will next week for the series.

What more can I do to convince you guys that OOB (out of the box) settings are no good for a consumer display, or for your eyes? In fact, I find the factory "BUY ME, BUY ME!" settings on modern flat panel TVs are worse than the factory defaults on any old CRT tube I've EVER seen.

The backlights themselves are really just too blue. This is a problem of sorts when laptops went from CCFL backlighting to LEDs- the color temp went way too high. It can probably be adjusted, somehow, but it doesn't help the color is just wrong to start with.

they all match pretty much, even in a place like best buy. All those cheapo LCD panels are probably coming out of the same 3 plants. Nobody cares about special phosphors or dot patterns or shadow masks like in CRT days. Sure there's cheap and expensive display panels, but they just don't seem to vary all that much otherwise.

Even half brightness, they're still too blue too look natural.

I'll restate what I said before- LCDs lack the color and brightness variations that affected CRTs. Default settings have always been and are still pretty horrible, but at least these days if you buy a demo LCD TV, it's safe to say the thing isn't already worn out like a CRT would have been trying to dazzle customers with every setting turned way up.

For viewing at home, I use an Epson projector that seems to have 3 CCDs and the starndard arc lamp. I forgot what the default factory settings were, but they were garish and made even the OSD menu setup hard to look at. It had to be something like high brightness, 14k color temp and no doubt some sort of vivid control cranked way up. I did not bother with any real calibration, but made sure white looked white and the brightness was reduced so that set so that "black" on the screen looked black, even though the screen itself is white.

How do you suggest adjusting a projection system?

WHite LEDs are actually blue, with a phosphor to make it into something near white light. They fail in that attempt.