AVS Special Member
Join Date: May 2008
Location: San Francisco - East Bay area
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One thing you have to understand about written calibration "procedures" (like "do color luminance first, then do ___________, then do _______________) are not EVER requirements. And they are unlikely to apply for EVERY calibration... in fact they often don't even apply to MOST calibrations. And in some cases, for some video displays the any given written procedure could be WRONG in that it won't work for one reason or another.
Your job as a calibrator is to START SOMEWHERE, pay attention to how the TV responds. If it does something you don't expect, figure out what it is doing that is different than your expectation and WORK AROUND it by modifying the procedure you were going to try to follow in any way you think might be more appropriate for THAT TV/projector. A Pro calibrator with a lot of experience is likely going to make those decisions quicker and with more certainty that someone who has taught himself calibration and has calibrated 1 or 2 different video displays. There is an advantage to just having to know 1 or 2 video displays... you can spend a LOT of time on them figuring out their response and how to best calibrate those 2 displays. And it will take a lot of time. More time than a Pro can spend on a calibration in a single work day.
LUT calibrations are, undoubtedly, the bomb when they work right. And more points are always better than fewer points. 125 points is a HUGE advantage over 26 points or 16 or 8 points you calibrate while doing a conventional calibration. Thousands of points is better than 125 points (obviously, duh - does not require an argument or telling someone they don't know what they are talking about). But there are only two devices that currently support video calibration LUTs for home theater... Lumagen Radiance processors, and the eeColor box, neither is particularly cheap. If you were using an HTPC with the right sort of video system, you might be able to have a software app for LUT calibration with thousands of points, but I'm not aware of such an app for home computers existing today. HTPCs have their own set of problems though, and a lot of people simply don't want to deal with a home computer being the only source component for their home theater system. Consumer TVs today don't directly support LUT calibrations so if you don't have a Radiance or eeColor box and software capable of creating the appropriate LUT to load into the box you are using, all the discussion about LUTs is un-helpful in the extreme.
Back to the original topic - It boils down to nothing about calibration ever being "this way" and "this way" only. You have to find your way. Remember there was one Harry Potter movie (and book) that described how the corridors and stairs would move constantly so you always had to discover a new way to get to where you were going? Same thing with calibration... you may find doing grayscale first works most of the time, but are you paying enough attention to what the TV is doing to realize that there may be a time when you have to do CMS before grayscale in order to get optimum results? This is all part of the art of calibration. Calibration is a process that is constantly fluid and variable. That's why there has never been a single place you could go to find written calibration instructions that will lead you to the best possible calibration every time. With the current state of things, that's simply impossible. Every calibration procedure you ever see written down is guaranteed to NOT WORK just about as often as it DOES work (some variation there, of course... some written things may only work 25% of the time, while others might work 75% of the time).
The next issue calibration has is how do you define whether a process worked or not? Take good calibration software like CalMAN... up until version 5, you verified your calibration by looking at your results for 2 grayscale adjustments, 10 (or 11) grayscale adjustments or 21 grayscale adjustments (depending on the display and video processor being used) and by looking at 6 colors. CalMAN 5 comes along and makes it easy to automate checking calibration results in FAR more detail... with so much more detail, you can find problems you didn't even know existed if you had an earlier version of CalMAN (unless you did extensive manual measurements of points you never look at with the 2, 11, or 21 step grayscale and 6 point CMS the previous versions used. With version 5 you now have automated confirmation options to check MANY more points. Now you may see problems you never saw with previous versions. That might lead you to find out (eventually, after much trial and error) that 75/75 color patterns work better for your TV than more conventional 100/75 patterns.. Problem is, until someone has TRIED this and found it works on multiple samples of the same video display (with measurements to show that it works), then documented it somewhere (probably specific to the video display in question as this may be a WORSE procedure for other models or brands)... you are out there on your own having to try different options to see how they affect your final (and much more complete) post-calibration measurements. And you still have to visually evaluate the images to make sure something bad didn't pop up during the calibration process (example, I've seen Toshiba video displays that would have HORRIBLE images loaded with block artifacts and posterization if any of the color calibration controls were moved more than +/- 3 (control range +/- 10) and just a year or 2 earlier, Toshiba TVs had CMS controls with ranges of +/- 30 and you couldn't use more adjustment than +/- 10 before the images would turn to total crap. You won't find that written down anywhere unless you read my reviews and kept a copy or made notes). Every video display is a puzzle and there's no one solution that is necessarily the answer for any given model because there might be 2 or 3 or 6 firmware versions released during a production run and they might all require different techniques.
"Movies is magic..." Van Dyke Parks
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