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Discussion Starter · #1 ·
I see lots of references to the amount of tweaking/calibration that is needed to get the best quality image with a D-ILA projector and an HTPC. Many folks talk about sending their projectors in to be calibrated, for example, after they get them.


If I use the DILARD program, and follow the various tweaking procedures described in this forum, would I still need to have the projector professionally calibrated to get the best image out of it?


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- Dan Butterfield
 

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Hi Dan,


The quick, non-politically charged, short answer is:

"Not Yet"


If you wish to have a fully calibrated projector today, you will have to arrange to have this done as a service and ship your projector to a person who can do this for you.


Dilard will be able to perform a full calibration only after the the addition of the last two Wizards (Gamma and Shading). There is also a new Black Level Wizard coming.


These last pieces will allow you to perform the calibration on your projector at home with a computer.
 

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Poitics schmolitics.


There is no war. A little heat from time to time, but no war, no battle.


Two totally different options for two totally different types of users. You want simple? Send your Pj away and feel confident that you'll get what you pay for.


Go the Dilard route and have a hands on part in making your Pj the best it can be.


No politics. http://www.avsforum.com/ubb/smile.gif


Chris
 

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Mark,


Let me guess. The present difficulty when using the

Black Level Wizard is not being able to "see" how color

is being changed while making the adjustments. Will the new

Black Level Wizard remedy this? Am I warm?


Bob
 

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Perfect. It is quite difficult (read: almost impossible) to keep the colorimetry correct while using the BL Wizard without quite a bit of bumping the "adjustments" on the end. Even then, the colors are hard to balance.


That will be fixed.
 

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Remember O great Americans http://www.avsforum.com/ubb/wink.gif that your forum is so attractive that it became an international forum, probably the number one in the world for a long long time to come.

So, a lot of readers, including me, enjoy the learnings of this forum and apply it to ourselves. And to send the D-ILA for a personal tweaking from the other side of the world (and back!)is not a reasonable option. So I am truly grateful to MArk Hunter that I can hunt down at my own home, all mis-alignment that keep the D-ILA from his perfect state.

Ky
 

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Neil-

My projector was calibrated by Cliff Plavin who performs the AVS calibration service. Excellent results for me! Another excellent source is William Phelps in Palo Alto CA (search for his e-mail address on this forum). Without attempting to speak for others, I think the consensus is that these 2 sources currently produce the best calibration. They have developed a calibration process and software that produces the best results to date. a great value!


I agree with Chris' post above. I think there is plenty of market for a Service and for those who wish - a self serve calibration via Dilard.


I personally recommend both for DILA owners. Dilard provides (will provide) tools to backup your professionally calibrated state, perform your own calibration, and return to the saved state (or any other for that matter). The professionally calibrated results have produced a standard by which all changes I make myself are measured. The picture from the calibration Service is just spectacular.


ken
 

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The other option for calibration is JVC Digital. I had mine done there, only because it was the only option available about 6 months ago. Correct me if I'm wrong, but I don't believe that anyone has found JVC Digital's calibration to be any better or worse than William's or Cliff's. I hope it isn't!


- Dave
 

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A lot of people have stated that they think the professional calibration is a great value for the money. Anybody willing/able to mention how much these things typically cost? Currently trying to make the decision between a D-ILA and the DWIN Transvision. From what I have heard (and please correct me if I am wrong), the DWIN requires less tweaking than the D-ILA and can be made close to perfect (or at least as perfect as it can be) at home. If this is so, then I would add the cost of professional calibration to the D-ILA when making the comparison.


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Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you're a mile away and you have their shoes.
 

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The Dwin projector as with other DLP projectors suffers mainly from the use of a UHP Halogen based lamp. These lamps are the source of the problem regarding proper Grayscale tracking of the projector. The Gamma Curves for the projectors look-up-table are created with a new lamp which has spectral characteristics which rapidly decay over the first 50 hours of use. Typically the Red content of the lamp becomes almost non-existent and drives the projector to look too Blue. This color shift is on the order of 2000 degrees Kelvin which is very bad for accurate video reproduction.


The R,G,B White Balance and Gamma adjustment in the Dwin projector will not allow you to completely remap the gamma table. It will typically allow you to readjust at Black and White. The manufacturers need to become more knowledgeable of the lamps characteristics and provide a gamma curve designed for when the lamp has decayed and stabilized in its lifespan. This will allow the color reproduction to be be consistent with proper video for the majority of its output rather than the minority.


The DILA projector by utilizing the more costly Xenon lamp which provides a more accurate light source which remains very stable throughout its lifespan is a key factor in what makes the projectors image so good. After a DILA projector has been calibrated the only variable is when the lamp will need replacement. The picture quality is relatively the same for the entire lifespan of the lamp. This is not the case for DLP projectors.


If you were to remap the gamma table in the DLP projector it would be good after the lamp was approximately 50-100 hours old. At that point only the intensity of the light output will slowly degrade.


[This message has been edited by ghibliss (edited 05-23-2001).]
 

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The going rate for a calibration by AVS/Cliff or William is ABOUT $500. Please consider that a ballpark because I don't know if prices have changed over the last few months. There may also be discounts provided by AVS if you purchase the projector and the cal from them and it may be a little higher now if the demand is up. Check with AVS and William to get the actual numbers...


I don't know anyone who has done a direct compare to the JVC calibration. The postings describing the AVS/Cliff and William calibration results have been extremely positive. I haven't seen any postings of JVC calibration results -


then again I probably just missed them-


ken
 

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There are no consumer proejctors that will allow you to remap a look-up table currently. This is not generally possible to do as it involves an extensive number of measurements to be made from the projector in a totally light proof environment with accurate instrumentation. After the measurements are made software to calculate what the new table values need to be and then uploading the data back into the projector is required. This is far more than the typical consumer is equipped to perform presently.


Some projectors (Sony LCD) allow gamma adjustment which is greatly expanded over what most competitors allow. Their adjustments allow up to 560 separate adjustments to be made to correct for the gamma circuitry. With out instrumentation and a calibration procedure for any projector that has the capabilities for gamma correction you would be well advised not to try to recalibrate it yourself. The Sony projectors do not have the ability to save and restore the settings of the projector via rs-232 to a file. This means that unless you record all of the values from the software prior to any changes you will have a very difficult time of restoring it to factory values.


Regarding the need to recalibrate the JVC DILA projector periodically: the need for this is minimized greatly by the fact that the projector utilizes a Xenon lamp vs competitors Halogen based lamps. The Xenon lamp is extremely stable both in color output spectrally and light output over time. The Xenon lamp is the same type of lamp used by Film Theaters because of this very reason. Halogen lamps on the other hand are used because of size, cost, and light output. The Halogen lamps major drawback is that the color temperature shifts drastically in the first 50 hours of use towards Blue by an incredible 1,500 to 2,000 degrees Kelvin (depending on manufacturer and model). Due to this color shift of the lamp the projector which looked excellent when new out of the box rapidly deteriorates over a short time frame and allows minimal correction to the user for proper video calibration.


The LCD/DLP projectors will benefit from periodic tweaking of the White Balance circuitry to an extent. The reason why the White Balance adjustment in most of the current projectors is ineffective is that it only addresses the Black and White point calibration of two points in the gamma curve. This leaves the majority of the curve unchanged especially at the mid range where fleshtones are located. By correcting only two points the installed look-up table has worse linearity than it did prior to the correction!


The gamma curve is designed for the projector with a new lamp installed, once the lamp has aged and its output characteristics have changed significantly the gamma curve is not accurate for the display any longer. DILA lamps are more expensive than Halogen but the performance and resultant picture quality clearly show why!


Manufacturers (generally) do not make available software with the capacity for recalibrating gamma look-up tables. The DILA projector is one of the only devices presently available that allows accurate calibration via serial connection and special software.


[This message has been edited by ghibliss (edited 05-24-2001).]
 

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Ghibliss,


Thanks for the thorough explanation. Just want to confirm a couple of the things you said. Am I right in concluding that there is no way to "re-map the gamma tables" on the DWIN from home? Would there be a way to have that done professionally?


Also, it sounds like you need to do periodical calibrations, even with the D-ILA. If you get a new bulb in the D-ILA, would you need to re-calibrate? That would be a big plus for the D-ILA if the Dilard software will let you do most (if not all) of the necessary calibrations at home, relatively easily.


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Before you criticize someone, you should walk a mile in their shoes. That way, when you criticize them, you're a mile away and you have their shoes.
 
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