Misubishi Widescreen RPTV Calibration Pointers Wanted

Discussion in 'Archived Threads 2001-2004' started by Doug_L, Nov 1, 2002.

  1. Doug_L

    Doug_L Stunt Coordinator

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    Hey all,

    Heading up to a friend's house tomorrow to set up an audio system and calibrate his new Mitsubishi WS-55411 (or maybe 55311). Not sure that this is either the latest, or best, RPTV out there, but he got a pretty good deal. I'm a CRT guy myself, so I'm looking forward to this new challenge.

    Anyway, this is a first time for me calibrating a RPTV, and I'm wondering if there are any general pointers for me. I also have some specific questions:

    -As the TV's only had about 15 hrs viewing, it is worth it to do a full 64-point convergence?

    -If I'm used to CRT calibrating, and truly black blacks, do I need to change my expectations? Should I even try and use a PLUGE pattern, or is that a lost cause on RPTV's?

    -Mits have a manual color adjustment for 480i sources, with slider adjustments for Magenta, Red, Yellow, Green, Cyan and Blue. Is this basically a poor man's greyscale adjustment? Note that there are seperate color temperature adjustments possible to use in conjunction (ie: low, med, high). What would be a good test pattern (on Video Essentials) for me to use?

    As I said above, I'm heading there tomorrow (Sat. Nov 2) so any comments that could be had ASAP would be great.
     
  2. Robert P. Jones

    Robert P. Jones Second Unit

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    Mits's throw up one of the finest images on the market, once fully and properly tweaked.

    AVIA and VE - and the ISF Optical Comparator - are all I use, and I calibrate Mit HDreadys all the time. The unit you're visiting is CRT based, right? Or is it their DLP? If it is CRT, the same things that apply to FPTVs also apply to RPTVs, tho blindly following VE's pluge directives for setting brightness will work fine on FPTVs, but on very few RPTVs.

    To set Brightness, I use some selected starfield scenes from Starship Troopers, myself.

    VE pluge is best for greyscale, AVIA's greyscale patterns are flawed.

    I suggest using the Cantilever Technique for the manual/optical focussing, which can be used on both FPTVs and RPTVs. You can find a writeup about it on the Keohi website, under my name in Expert Tips section.

    Am not familiar with these registers in the Mit's that talk about cyan, magenta, etc. Where are they?

    You must be a FPTV calibrator, right?

    Mr Bob
     
  3. Ron Boster

    Ron Boster Screenwriter

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    Try running a search for your questions at www.hometheaterspot.com They are a group of Mits owners/tweakers that hang out at that site. You'll find a TON of suggestions and tweaks that others have tried on their Mits.
    Good Luck
    Ron
     
  4. Doug_L

    Doug_L Stunt Coordinator

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    Mr. Bob:

    May have given you the wrong impression; I'm really just a CRT enthusiast (albeit with expensive/good taste as evidenced by me Loewe) who's looking for some user-level tips and hints.

    As for the color adjustments, based on the manual, there is an advanced feature for the color balance that applies to all 480i signal sources and affects all inputs. There is an Auto Color Correction which "optimizes skin tone color", but thankfully, can be turned off. When Auto is off, you can adjust the six above colors (previous post) manually, which seems like it may be a poor-man's grey scale adjustment, or at least a way of taming red push (which the unit may, or may not, have).

    Was actually on Keohi while you posted reply. Will check hometheaterspot, as well. Keep those ideas coming.
     
  5. Gregg Loewen

    Gregg Loewen Video Standards Instructor, THX Ltd.
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    480 i has color decoder adjustments on the new lower end Mits. This has nothing to do with gray scale. For 480P and 1080i the EEPROM has to be reflashed to corrected properly (or you can simply use an attenuator). On the new higher end Mits color decoder adjustments can be made within the service menu.

    Doing convergence work is ALWAYS worth while!!

    Enjoy!! It is always fun tweeking out a new set.

    Gregg
     
  6. Doug_L

    Doug_L Stunt Coordinator

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    Wow! Responses from both Mr. Bob and Greg Loewen. I must have done something right.

    Thanks for the advice.
     
  7. Robert P. Jones

    Robert P. Jones Second Unit

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    At 15 hours, there will probably still be some drift no matter how good you get the convergence, until the first 100 hour "drift period" has passed.

    But some people just can't wait. I HAD to do mine immediately on my 65" Panny, it was so bad OOB!

    It can always be retweaked for finer precision later, after 100 hours, but I agree with Greg - do it now also, of course!

    Mr Bob
     
  8. Doug_L

    Doug_L Stunt Coordinator

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    UPDATE:

    I hooked-up my friend's sorround sound system and calibrated his new Mitsubishi 55411, and it looks a whole lot better than it did, but I have a few follow-up questions.

    1) When doing the convergence with the 64-point pattern, the blue image ALWAYS showed on both sides of the white lines/points (ie: I could never get the blue to dissappear completely behind the white line). Is this a possible error on this specifc unit that can be fixed, or is this a standard quality of the blue CRT, that it tends to be less focused? In other words, if this problem persists after 100 hours of varied use, should this be fixed?

    2) I also noticed when I was converging the TV that the right 4" of the TV were somewhat unfocused for the entire height of the TV (ie: not just in a corner). Although there is audio gear (and a subwoofer) on that side of the TV, none of it was there when I saw the lack of focus, so I don't think that's the issue. Again, is this unit specific, or is this endemic of either RPTV's, or specifically, Mitsubishi RPTV's.

    3) The red push on this TV, as stated in many reviews, is pretty severe. I had neither the time nor the inclination to get into the service menues, but I imagine that there's a way that I could tame it down a bunch, right?

    4) Even with contrast down at about 15-20% (no number, just slider bars) the set's ability to hold black at black from the high APL pluge pattern to the low APL pluge pattern was pretty bad. In the end I had to push the brighness pretty high up and hold contrast really low, and there still didn't seem to be a whole lot of shadow detail. Will this get better with age/settling of the tubes?

    As for ISF calibration I'd say there's about a 10% chance this guy would want to spend the money - he probably wouldn't notice the difference. I might have to make another trip in a month or two, though, to try and fix the red push and maybe play with the geometry a bit.

    Thanks again.
     
  9. Robert P. Jones

    Robert P. Jones Second Unit

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    The blue is never going to be as perfect as the red or green, but the decider is whether you can see this "blooming" from your regular viewing distance. At 2 feet, you will always see things at this stage of the evolution that you are not supposed to be seeing. I sit 8' back from my 65" Panny, and consider that the optimum viewing distance for a 65". But I do my convergence ops at around 4'.

    Make sure the optical/mechanical focus is dead on. Again, I recommend the Cantilever Technique. Once that is dead on on all 3 guns, the only focussing left is the electrostatic, at the focus block.

    DO NOT TOUCH THE SCREEN CONTROLS WHEN YOU ARE REACHING FOR THE FOCUS CONTROLS, ON THE FOCUS BLOCK!!! You'll destroy any precision the factory may have instilled in your greyscale if you do.

    If you can see this blooming on any color, esp. blue, from your regular viewing position, you'll have to focus the electrostatic a little tighter on that color. But if you change the blue elec focussing in any way, it will automatically change the white balance of your greyscale, with the action of the blue drive being mimicked by the blue focussing.


    The red push can be tamed in COMPONENT - not RGB, S or composite - by adding a variable attenuator from Radio Shack onto the red Pr component line. You'll need to outfit it for use with RCA connectors, as it comes with RF F connectors, in and out. But after installed, you can achieve correct linearity in the RGB color levels, entirely defeating red push.


    The unevenness of the focussing can be remedied via correcting the Scheimpfluge.

    What you are talking about is Scheimpfluge, or the angle at which the CRT hits the lens, then how the lens hits the screen. After all, in an RPTV, those angles will NEVER be parallel.

    So each of the 3 lenses is angled/tilted to compensate, and not always correctly, when they set everything in stone inside your RPTV for mass production, including the angles of the lens mounts. The big ceiling projectors have highly precision spring loaded adjustment setting screws for this purpose - the purpose of highly precision changing/altering of these independent lens angles.

    Using washers as shims on one side and not the other under the mounts where the screws hold your your RPTV lenses in place, can make it symmetrical all across the screen, side to side or up to down or corner to corner - depending on what you are needing to work on. After Sch. correction you may still have problems with center vs. side equality, but up to down or side vs. side - or corner to corner - equality/symmetry is what we're talking about here.

    You may have to play with the thickness of each shim, to finally get it right.

    Be sure to tape these washers/shims in before final securing of the lens on top of them, so they don't fall out later and into the works down below, when it is time down the line for coolant cover cleaning, under the lenses.

    I just had to do that on a Pioneer 510 yesterday - the blue had exactly the same differing focus response, left to right. Putting in 1 washer each under the mounts where the screws are, at the 2 nearest to center screws holding the blue lens in, did the trick, by angling the blue lens OUT just a little bit more than it was designed to do. But then it was obviously designed incorrectly, which is not uncommon in RPTV production units.

    You may have to recenter your image just a bit after this op, of course, but just changing the angle involved with shims does not really impact the direction of the image beam much at all, does not really tow it off its mark at all. The difference it makes in getting the focus symmetrical all around and thus CORRECT, on the other hand, is phenomenal.

    In my case, it still wasn't perfect, center to sides - the more expensive big ceiling projectors also have a secondary wingnut set on each lens for this center-to-side focussing purpose - but now the error at each side was at least identical to the other side's error, cutting in half the original error on each side. It was symmetrical now, in its focussing, side to side.

    Up to down error was not in question here, but could be on other units, and is correctable in exactly the same way as side to side error.

    As far as center to side symmetry, the Mit and Panny lenses have much better center to side design than the Elites do, and I think this is because of the slight dip they have in the center of the curvature of each lens, at least on the Mits.

    And where exactly to put the washers may be just the opposite on your set.

    To vary the angles involved, unscrew the 4 screws that hold your lens onto the chassis of the TV about 1/8" each. This will allow you to swivel each lens and change its angle in any direction desired.

    DO NOT TOUCH THE RED SCREWS. They contain the coolant, and if they are released/unscrewed, there is a clear and present - and IMMEDIATE - danger of coolant leakage.

    Forget about this on the really older Mits's - the lenses on them were secured from inside the works, and required the removal of the CRT to get to. But then I have never seen an older Mit need Scheimpfluge adjustment, either.


    The best way to accomplish knowing exactly where to place your shims is to defocus the optical/mechanical WAY OUT - so far out that the grid lines - internal or external, doesn't matter - are a half-inch to an inch thick, at your screen. That will tell you much more graphically what to do. On one side of your screen they will be wider/thicker than on the other side, when there is Scheimpfluge error. It is much harder to tell exactly what is happening - and thus what needs to be done - when the unit is properly focussed and the grid lines are tight in the center.

    Then when these thick lines are balanced, left to right - or up to down, or corner to corner - resecure your lenses, refocus the optical for real - I suggest the Cantilever Technique - and you're balanced and symmetrical in your optical focussing, like it should be.

    Then check/trim the electrostatic, avoiding the blue electrostatic trimpot unless absolutely necessary because of greyscale considerations, correct astigmatism errors if necessary - and if possible, considering that the first 3 years of Mit HDreadys did not have astigmatism correction magnet sets on the CRT necks of their units - and you're there, as far as focus goes.


    Gamma - the GMMA register in Video Chroma service menu - controls the level of black detail in the dark areas. It may need to be played with. But I usually never need to change this on a Mit, on regular viewing material. The dark castle scenes in Shrek, where we first meet the dragon, are great scenes for setting this.

    The optics have to be absolutely clean, however, before you can believe anything regarding shadow detail. The light path ALWAYS needs to be completely unimpeded as far as matting of dust goes, even under the lenses at the CRT coolant covers. Individual particulates are OK, since everything in the light path past the CRT faces will be out of focus till the image gets to the screen anyway. But mattings of dust have to be dealt with.

    Since this is an ultra new-gen set, I don't expect too much dust will be on the optics at present. But using a fine photo or cosmetics brush on the lenses, to scoop any dust to one side and then off the lens, couldn't hurt.

    The way to REALLY know your optics are dirty is to take a flashlight and shine it onto the lens or the mirror from the side, picking up anything on the lens at an oblique - as close to 90 degrees as possible - angle. That shows up the dust immediately, if it is there at all, with or without matting, which will also be highly visible that way.

    If there is a matting of dust, I can usually draw a happy face in it, tho I do wet my finger before I do, so as not to scratch the lens, which is usually made of plastic and VERY sensitive to being scratched, and permanently.


    Mr Bob
     
  10. Robert P. Jones

    Robert P. Jones Second Unit

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    Sorry, disregard, double posted.
     
  11. Greg Kolinski

    Greg Kolinski Second Unit

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    WOW Robert!!!![​IMG] VERY informative post. being new to high def RPTV's ,just bought a JVC AV56WP30 ,I had some of the same issues that you discussed.Being a different brand I would think each has it high and low points,but so far the JVC seems to have less "visual type"problems than the other manufacturers,but the red push is what got me to your post,[​IMG] .DVD clarity is very good,even comparing Progressive vs interlaced ,my progressive is the Panny 434[​IMG] so semi progressive[​IMG] ,does the up-convert of everything to 1080i cover a lot of the Panny's faults?
    Anyway,wonderful post[​IMG] ,definitely helped a newbie very much[​IMG]
    Greg
     
  12. Robert P. Jones

    Robert P. Jones Second Unit

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    What does "semi-progressive" mean?

    I know the Pioneer 434 does not have 3/2 pulldown, and is thus panned universally, but I have never heard of the Panny 434. The Panny RP56 has the flagship Sage/Faroudja chip that is "stealth" rated.

    Also, what does the "everything upconverted to 1080i" mean? I don't know of any equipment outside of HTPC that does that, and if such equipment does exist, it would have to be very high echelon, like Faroudja class.

    Mr Bob

    PS - I did a cal tour in your neighborhood a couple of years ago. Would love to come back. Are you maybe interested in forming a cal tour - getting a few compadres together and flying me in, to cal your sets?

    You can see one I've cal'd - mine - at my website, below, if you wish.
     
  13. ArnaudP

    ArnaudP Stunt Coordinator

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    Mr Bob:

    "DO NOT TOUCH THE SCREEN CONTROLS WHEN YOU ARE REACHING FOR THE FOCUS CONTROLS, ON THE FOCUS BLOCK!!! You'll destroy any precision the factory may have instilled in your greyscale if you do. "

    A few week after I got my new Mits 48311, a local service guy came over to adjust the TV. He actually played with the Focus Controls (the red one I believe) to correct the red push! Of course it did not do anything and actually might have messed things up. Can I reset the Focus Controls to factory default?

    Thanks
     
  14. Robert P. Jones

    Robert P. Jones Second Unit

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    If he played ONLY with the red focus, you're OK.

    If he ACCIDENTALLY played with the blue focus or ANY of the 3 screen controls on the focus block - very possibly the red if you were concerned about red push and he is as clueless about how to handle red push as you are making him sound - you might have cause for worry, in your greyscale. The blue focus mimics the blue drive in an inverse manner, affecting the white balance of your greyscale. The red screen control must not be touched any more than any of the other 2 screen controls, unless the toucher is prepared to entirely redo the greyscale.

    Red push has nothing to do with greyscale. It is a color decoder issue, and the only place greyscale has in that is that any stray colorations - eliminated thru correcting the greyscale - could affect getting the color decoder correct instead of imbalanced in favor of the red, which is what red push is. Therefore the greyscale should ideally be done before any red push ops.

    Red push is a color imbalance built in by Mit, and another word for it is blue-green diminish.


    The focus controls are mechanical, there's no way to reset them to the factory default if altered. You simply focus them again, the best you can. If it's blue, you kiss off any chance of recapturing the proper position unless this is one of the new gen sets, which were maximized at the factory on electrostatic focus on all 3 guns - with the new more powerful CRTs, they no longer precision-defocus the blue on most brands - in which case you simply refocus it to its tightest and you're back where the factory had it.

    This is probably the case if it's this year's model, which yours obviously is - if so, just maximize all 3 and make them their tightest.

    But don't accidentally grab one of the screen controls when you are reaching for the focus controls...



    Mr Bob

    PS - Portland is my home town, and I go there every few months. Let me know if you want me to cal your set while I'm there next time.
     
  15. ArnaudP

    ArnaudP Stunt Coordinator

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    Mr Bob:

    First of all, thank you for your answer. Unfortunately, he did touch the screen controls in addition to the focus controls. I know that he did "play" with the red screen control. It sounds like the greyscale is messed up now. Would you be able to fix it for me? Please let me know next time you are in the Portland area. I would like to have you work on my set.
     
  16. Robert P. Jones

    Robert P. Jones Second Unit

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    Yes, I can fix it for you.

    email or call me with contact info.

    Mr Bob
     

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