The Secrets of Professional TV Calibration : Mysteries Explained

By Douglas Mechaber, published on January 26, 2009
Source: Tom's Guide US | Keywords: , , | Themes: Display Panels and Monitors, CES Las Vegas

1. Mysteries Explained

Learn to calibrate a TV or monitor? No big deal–or so I thought. The two days (and evenings) I spent listening to Joel Silver, co-founder and president of Imaging Science Foundation  (ISF), were literally eye-opening. Over 30 interested students, from across the United States and overseas, gathered at a home-theater store on the outskirts of Las Vegas for the ISF Certification Course.  This is normally a 5-day course, but ours was crammed into two days.

The depth of the course was astonishing, from the history of TV to film resolution to differing standards. For example, this course taught me to quash the videophile's cherished belief that film is the gold standard of image quality. But a simple test reveals something else. The next time you go to a movie, close your non-dominant eye, pick some words on the screen, make a “V” with your two index fingers, hold your arms out in front of you, and focus on one letter.  What will you see? The letter jumps around - a lot.  Most people think film is a pristine 24 frames per second.  It's actually 48.  There's a black shutter that comes into play after near each frame.  The effect you see is due to the imperfect alignment of sprockets and gates involved with the projection mechanism. Hardly perfect.


I also learned another seldom stated fact:  HDTV has existed since the 1930s!

In between all these topics, Joel regaled us with stories of interesting clients, how to handle the stickiest of home-theater problems, and TV manufacturer’s shocking lack of technical know-how.  Each story had a point to help us remember a particular principle about customer service or calibration. We learned about color matching and test patterns before we were cut loose to fix the classroom TVs that were expertly “mucked up” by several Sencore representatives who had joined to help. 

A scanning electron micrograph of a TI DLP chip.

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audioee 01/26/2009 11:20 PM
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Please fix the corrupted images.

der juden 01/27/2009 12:58 PM
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Yes please fix the corrupted images if you can. Great article as far as a subject, but you aren't really saying much at all. I know you probably absorbed alot of information in those 2 days, but your really not telling us anything other then "the TV companies are lying to us" which I wholeheartly agree with, not to mention the monitor companies (I work for one). If you could post update your article with more information about the ISF, and cover a few of the topics they covered in detail it would really make for a great article.

plasticwhale 01/27/2009 7:15 AM
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How does this calibration differ with the calibration done by $200 colorimeters for PC monitors? Will we ever see TV's with built in colorimeters so I don't need to have someone calibrate it for me?

cjb110 01/27/2009 9:13 AM
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As I know some people have an issue with Monster products, the DVE range, is also great for calibration.

michaelahess 01/27/2009 9:19 AM
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DVE all the way, this was a monster/isf ad, nothing more. My $100 calibrator provides consistant results over 4 22 inch computer lcd's, a 32" lcd tv, a 42" plasma, and a dlp projector (use rear projection to calibrate). Spend some time studing the basics and get some quality gels, then do it yourself for a fraction of the cost. Plus you can tweak it to YOUR idea of a perfect image, not that of a machines.

neiroatopelcc 01/27/2009 1:18 PM
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Very informative article. I don't think I will need it for any particular purpose, but interesting read anyway. More of this stuff please. Especially the part where you check if manufacturers care or know about it.

JWL3 01/27/2009 5:50 PM
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No one wants to spend $500 or more for some guy to come over and set your tv for you. The solution to this is for the manufacturer to print on their website for each model the calibrated Black, White levels and color temps etc. Just like CNET and some other websites do the professional calibration on each model and list it so that purchasers can simply adjust their tvs themselves. A huge help for us.

lamorpa 01/27/2009 6:36 PM
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Beyond basic home calibration these 'pro' calibrations might get you a 3% better picture. Of course, typical room conditions vary 10-20%. Professional calibration definitely changes things for you - it makes your poorer.

Anonymous 01/28/2009 3:18 AM
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To plasticwhale. I work in the broadcast industry as a motion graphics designer and I have a TV monitor in my room that is self calibrating. It is also happens to be a 20" CRT that weighs 70lbs and costs $40,000 so go figure.

In regards to 240Hz, of course you can see artifacts. The TV is creating them with a fast (quick to compute but sloppy) motion interpolation algorithm. When we do motion re-timing for a shot like a speed-ramp ala 300 it is an immense amount of work to avoid artifacts. Important shapes in the scene need to be roto'ed frame by frame to make sure the computer doesn't blur the edges of those shapes with movement happening in the background. After that is all done you usually still have to go back and do paint fixes where the computer screwed up. The software we use is some of the best and it can only calculate about 1 frame every second. I can't imagine how horrible it would have to look for for them to get the speed up to 24, 25 or 30fps. These TV's will only come into their own once we start feeding them signals of stereo3D content at 120Hz for each eye.

And finally to all the people that are worried that they have to have their TV calibrated, there is only one rule that matters in the end: Does it look good to you?

ediver 01/28/2009 5:02 AM
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I apologize for the pictures, now fixed. Entirely my fault - I zipped up the pictures... That was my undoing- somehow all those artifacts were introduced by zipping them to send to my editor! I should have double checked, but was sure that it was the content management system...


ediver 01/28/2009 5:27 AM
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I thought I did cover topics in the isf course. We spent some time on discussing contrast, how it is measured, and how one might maximize it. Then we looked at the TV brochures and compared our numbers

Other subjects: lots on the history of TV and image, and the science of color; surprisingly little time on how to adjust controls - it was just assumed you could operate a remote and dig in to the deepest menu, even on an unfamilar TV. Adjusting color space to get a dot centered isn't very sexy. Not only would the picture be boring, you have to alternate colors, and go back, just as I described with adjusting contrast and brightness. That is most of the course. I had to be fair, too, it wouldn't do to give away all the course and secrets, would it? Besides, no one would read that detail.

As far as the worth of the isf calibrator - as someone observed - it's all about educating the customer, to get the best picture possible with customer's TV and disc players/scalers, and to make the customer happy. The $500. price is for multiple inputs - each input has to be calibrated separately. What changes is that same model TVs are not identical; room conditions are not similar; and inputs (DVD, Blu-Ray players, receivers, scalers) will not be similar. So the other part of the time was spent largely discuussing how to please a customer, and how to judge motion artifacts so you can make sure the customer is using the best scaler - on the TV, in the receiver, or from an external box of player? - so you can get them the best picture. It's not only the actual set calibration.

Last part I'll address is the less expensive "colorimeters." We discussed a cheaper way in class that is more accurate than using the cheap devices. That's actually a test (to my editor) I am proposing to do - how do the cheap devices compare to pro level equipment (what do you get?), and the cheaper solution described in class (but not one an isf calibrator can charge for). Briefly that solution is to use a known light source D6500, I believe, to shine on a calibrated color chart. These charts - even the little ones - aren't cheap - about $35 -$50., and you build a light box to contain the light. That way you have known references to compare against test patterns on the screen. You would have to use DVD or Blu-ray test patterns, since a generator would be too expensive. I am surprised at the consistent results you claim; many reports on various forums disagree, to put it mildly. Pricier light meters are especially good at the extremes - very low lux - on the order of .01 foot-lamberts to over 100 ft-L. The inexpensive plastic meters just can't match that, nor can they do it consistently - but I want to check this!

I mentioned the last alternative, that some have found is about as good or better than a cheap colorimeter, and less expensive - that's the DVD calibration discs. As far as the difference between the DVE and the isf disc- both probably get you to the same place - one uses realistic images, the other test patterns. One has voice narration, the other you'll need a manual. The problem is that some of the critical test patterns are deeply buried in the DVE menu system. Most of the pros use the Avia pro disks, which have myraid patterns for just about every purpose (and priced similarly as well).

Hope this addresses the concerns. Good comments all - hope this is the start of more home theater type reviews here.

ImmortalJman 01/29/2009 6:16 PM
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That was a wonderful article. I love working with video and film and this is more info in the bucket for my use and has even peaked my interest in attending the class. Thanks.

Anonymous 02/02/2009 8:46 PM
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Ye gods. I'm on a fixed income so paying around $1,000 for a TV set is a hardship. Now I gotta have some guy drive over to my home (polluting the air I am forced to inhale) and then pay him for what should be a simple job of plugging a TV set? What the hell is on TV that is worth this time and money? MTV?I am disgusted with the younger generation and their spendthrift habits. And we are, fellow sucka, in a Depression.

Anonymous 02/03/2009 1:58 AM
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All well and good until your TV looses power and all settings are reset to factory defaults. I now use a UPS to prevent that.

neiroatopelcc 02/04/2009 9:10 AM
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Ligon :
Ye gods. I'm on a fixed income so paying around $1,000 for a TV set is a hardship. Now I gotta have some guy drive over to my home (polluting the air I am forced to inhale) and then pay him for what should be a simple job of plugging a TV set? What the hell is on TV that is worth this time and money? MTV?I am disgusted with the younger generation and their spendthrift habits. And we are, fellow sucka, in a Depression.



Younger people want those cool things you don't see the point in, but in fact it's your generation that has them! Those of you who used to have this 10K expensive B&O set in the 80s might've upgraded to something that provides style and quality, instead of just style. So while you complain about the youth, it's in fact not them who provide the marked for these things.
Its a bit like a 19 year old wanting an Alfa 156 GTA. That's all fine and shit, but he can't afford it. It's the rich bloke who has it as the first owner that creates the marked for the car.

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