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The only question not addressed in your summary is perhaps one that’s more personal… I submitted 10 calibrations to you, do I need to resubmit those somewhere else?

I did think of 1 new issue…

Is some sort of approval needed for use of the THX logo on our business cards or web site or other promotional materials?

If so, how do we get that approval?

And is there an official THX Logo Art image set we can download somewhere so we are using “official” logos?

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Any answers to the questions above?

I believe I have completed all the certification requirements, but I have seen nothing about getting listed as a THX certified video calibrator on the THX.com site.

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Also, if I’ve completed the certification requirements, how do I get a listing on THX.com?

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I just found out he is deployed right now and won’t be back in Savannah until September… and he hasn’t bought the Panasonic yet. He expects to be ready for a calibration in mid-late September. I’d be happy to send him your contact info, website, etc. Let me know.

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Any answers to the above questions?

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OK, the site came back up yesterday and the test worked. I passed, but would like to know what questions were answered incorrectly and what the correct answers were. You only get your % score and that’s it.

Re. automatic submission of calibrations for certification… is this for the first 10 calibrations you need for getting certified, or is this for getting the THX Calibration Certification for a customer’s video display?

If I submitted 10 calibrations to you and passed the online Tech 1 test, is that it for Video Systems 3 Certification? Anything else that needs to be done?

And a note on something I noticed… there are references in the training materials (Power Point slide set) to Video Systems 3 being the class/certification. But on the THX.COM website there are references to Video Systems 4 being the video calibration certification. What’s up with that? I can’t post a specific URL with the Video Systems 4 reference because THX.COM seems to be down again this morning. But I believe I saw that reference in more than 1 spot when I was looking for THX Calibrators with the search feature. And looking at info on the certification programs.

UPDATE: Here is the Reference to Video Systems 4: You go to http://www.THX.com/techs then login and after logging in you select Certifications and you get this listing of the certifications you have achieved. I didn’t copy over the URL since I assume it would be different for each person.

THX Certifications Achieved:

Official TitleTraining Level – Date Completed Video 4 2/17/2008

Completed Classes:
THX Certified Video Display Calibration Video 4

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Well, I have gotten the test and the “study materials” downloaded. I read the study materials and answered the test questions, but haven’t filled out the online test yet. I tried to do that last night and the site seemed to be down. I was going to fill in the test answers shortly. Should I wait? The test I downloaded has 27 questions – all focused on the THX certification process, THX modes & processing, and other stuff that seemed like what would have been in the Level 1 course. 1 or 2 of the test questions appeared to not be covered in the reading material (presentation slides) but they were easy enough to find answers to using Google.

Should I hold off on the test answers or go ahead with them today?

I just checked to see if I could access the test and it appears the site is still down as of 10:45am Mountain time today (Tuesday).

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Hi John,

I would like to have a go at the L1 online test, how do I get setup for that?

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I have a Harmony remote I don’t use because I don’t like the results you get downloading the codes for each component you own – and there are no downloads and little hope of getting any for some of the components I own. Will the codes for the Universal remote work the same in a Harmony remote?

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Well, I went back and had another shot at getting a decent combination of Gamma and gray scale. No one thing got the Gamma back from 1.65 to 2.1 where it was when I left.

I had been using Custom mode on purpose during the first calibration since it gives you more controls and I was getting a better gray scale. Switching to Cinema mode upped Gamma by around 0.2 and I spent more time massaging the gray scale which eventually got better.

I did move the sub-bright setting back to the 802 default and gave up on having Brightness in the user menu at 0 for easy reference, but that ended up not doing anything useful.

Moving Cuts & Gains did change Gamma though so I followed the setup procedure outlined in the Service Manual for this model which involves setting all 3 cuts to 80, setting Green Drive to C0 and adjusting only Red Drive and Blue Drive to get d6500 for a 100% white window. Once you have that, set All Drive to FC. Then you can fine tune cuts and drives as long as you don’t exceed FC for the weakest color on the Gain/bright end… so if Red is the weakest color, Red Gain should never be set higher than FC.

Doing that gave me another .18 or so, getting me back to ~2.03.

The last thing I tried was crushing the bottom a little. I ended up pushing 1% and 2% into black, 3% was about where you’d expect 1% to be. That gave another .07 so Gamma ended up right around 2.10. But I couldn’t find anything that would get the Gamma any higher than that.

The picture looked about like you’d expect… a little lost shadow detail, but not too bad. The Green primary is pretty high on these panels… nothing could be done to fix that. All 3 secondaries were “off” with Cyan and Mageta being counterclockwise from the ideal position and Yellow being clockwise from the ideal position, so again, nothing could be done about those.

With the higher Gamma, I had to give up having the 10% step almost perfect… it went Blue but nothing you could do about it. Forgunately it wasn’t so blue that it was distracting. The extra blue seemed to combat the panel turning very red 4%-6% since that problem disappeared with the new settings – and that red 4%-6% problem was pretty obvious, much worse than the blue-ish 10% step.

I may never have encountered the low Gamma problem with this panel if the owner hadn’t been calibrating it himself with CalMan and an i1 Display LT – and not writing down the factory defaults for Cuts/Gains. On the first Cal attempt the Cuts in particular were much higher than where they end up if you use that factory procedure. And even though Custom mode lets you do some things better than you can in Cinema mode, the loss of .2 in Gamma whenever you switch to Custom mode compared to Cinema was too much of a handicap with this panel. The gray scale ended up being quite good for 20%-100%, Gamma was much more reasonable at 2.1 and I got rid of that red-shift in the deep shadows that had been bugging the owner.

He ended up happy, and I felt pretty good about undoing the problem without having recorded factory defaults for the panel.

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It appears on these panels that if you set the Picture/Contrast and Brightness controls to their mid-point then use sub-bright and sub-contrast in the service menu to setup the black and white levels, the panel’s gamma is somehow thrown for a loop (way too low). Leaving sub-bright and sub-contrast alone in the service menu and using the user menu adjustments seems to produce OK gamma.

This is preliminary… I will be confirming this in 10 days or so when I go back to have a second shot. I will post a follow-up/update after that return trip.

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“Take contrast down really low”

How low? I already set the 100% white window to 26 fL. That’s where it is set when measuring Gamma at 1.65 for Custom and 1.85 for Cinema. At about 29 fL (for the 100% white window) the black level jumps up significantly.

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If it wasn’t clear, I did set black level using 0% and checked it with 10%, 20% and 30% to see how it held up… it was OK throughout.

The black level only jumped up when you displayed something that “pushed” the panel a bit like the 100% window at 29 fL or more. If you adjusted the Picture control 1-step at a time, there would be a 1-step increment that would cause the black level to jump way up. I ended up using the 100% window to set the luminance to 26 fL to make sure the panel stayed below the threshold where most of the shifting of the black level would not happen.

But that left me with Gamma at 1.65 in Custom mode and 1.85 in Cinema mode.

The numbers you mentioned were about right for getting rid of the red tint to the 10% step. I got that under control with no problem.

My only problem is that as good as every other measurement is after the calibration, Gamma is 1.65 for Custom mode, and 1.85 for Cinema mode. And there are no User controls or service menu controls for Gamma.

It appears that the only alternative is to put the panel back to the previous settings (where Gamma was 2.4 or 2.5) and leave all the other errors that I “fixed” with my calibration. My gray scale was much better than his – it was actually excellent with very low dEs. So it surprised the heck out of me when Gamma measured as low as it did. But he’s obsessed with the low Gamma. Before the calibration he was obsessed that the 10% step had red in it and that his black levels floated. I got rid of both issues, only to get hammered with the low Gamma.

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It was obvious I couldn’t do measurements while in the Service Menu the first time I did an exploratory measurement in Service Menu mode (I’d already measured the same thing before I went in to Service Menu mode), so, yes, I was already doing the measurements outside the Service Menu mode and only going into Service Menu to make changes to cuts/gains.

That method is what produced the measured Gammas of 1.65 for Custom mode and 1.85 for Cinema mode. As mentioned in the first post, I have very low post-calibration dEs from 10% to 100% in both Cinema and Custom which is reflected in nice flat temperature graphs and RGB graphs. I just couldn’t get Gamma anywhere close to 2.2-2.5. At least not while minimizing that goofy floating black problem (black level jumps up very noticeably if 100% white window luminance is set higher than 29 fL). The owner of the display, being the tweak he is, did his own calibration in January and measured 2.5 Gamma, but he had bad floating black issues and his RGB and temp graphs were far worse than what I left him with. His Gamma graph showed the 3 colors separating as luminance increased (the 3 colors were not tracking the same gamma curve). And his 10% step was very red which was incredibly obvious in movies. I’m beginning to think my “perfect settings” for the gray scale and elimination of the floating black problem put the display into a place where it simply can’t do Gamma. The owner specifically asked me (before the calibration) to eliminate the floating blacks and the bad red tint he had at 10% – and I did both of those. The cost appears to have been Gamma coming out at 1.65 in Custom mode and 1.85 in Cinema mode.

Does this sound possible/plausible?

Something else I noticed while looking through the service manual… it has you set Green Drives to C0 (C_Zero) (hex) and do all the adjustments with Red and Blue where it describes setting the setting factory color temps. Green Cuts also have a specific setting with all adjustments performed on Red & Blue Cuts. I did change the Green Drive settings a fair bit and Green Cut was adjusted a little to get the ideal gray scale tracking. Any possibility setting the Drives and Cuts back to the numbers specified in the Service Manual would put Gamma back to something more reasonable? I doubt I’ll be able to get the gray scale nearly as accurate without being able to tweak Green though… Red was “weak” compared to the other colors at high luminance (even though I was only getting 26 fL from the 100% white window) so I was reducing Blue and Green Gains a fair bit to get them in line with Red.

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