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adaseng,


The uncalibrated projector has an artificially high contrast ratio out of the box due to its inflated White point adjustment. This setting from the factory is made to achieve their specification for brightness at the expense of color accuracy. Once the projector is calibrated for a D65 color temperature accuracy you will typically see a reduction in Light output at 100 ire of approximately 20%. Since the projectors peak brightness has been significantly reduced the contrast ratio can be increased only through a substantial reduction in the light output at (0) ire Black.


To increase the contrast ratio over what the factory provided out of the box you must reduce the light output at (0) ire Black by a greater amount than the peak (100 ire) White level is reduced from the calibration. Ansi lumens are the result of averaging measurements taken from either nine zones or for Expanded Ansi 13 zones from the screen. This would prove to be quite difficult to do with an automated system utilizing one sensor.


[This message has been edited by ghibliss (edited 09-19-2001).]
 

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Hi Seng,


The Dilard calibration results consist only of:
  • Original Contrast (on/off)
  • Calibrated Contrast (on/off)
  • A graph of the 3 gamma tables


Dilard makes no attempt to calculate the ANSI Lumens and does not require measurements of distances from the sensor to the projector or image size at that distance.


At one point, I had a D65 graph to show that it is indeed flat, but pulled it because it really is a pretty boring graph (simply a horizontal line) and the Wizard doesn't have the space to display anything more than the above.


I use Colorfacts to verify the Wizard results myself (before and after), but this application is separate from Dilard and all of the information in it would be quite overkill for the auto-calibration results.


Thanks!


Mark
 

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Mark,


I know you are working hard finishing up with dilard 2.2 but can I request for the followings:


after auto calibration, have the following data on display:


before calibration:


ansi Lumen:_________


Contrast ratio:________


after calibration:


ansi Lumen:_______


contrast ratio:__________


I don't expect the lumen to change much but this feature would help us keep track of our projector lumen as the lamp ages (for those of us who don't have colorfacts).


thanks


seng
 
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