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Discussion Starter · #1 ·
Hey there all it has been a long time since I have seaked out information. I recently noticed on my 720 that in certain scenes I am getting a greeish/yelowish tone showing up. You can mostly see it on skintones and white images. If anyone has seen the move Babalon AD with Vin Deisel the scene where he is talking to the girl with the norther lights I have a VERY distince ban that crossed the entire screen. The image is of snow in the night.


I have paused at this scene and went threw every color setting, brightness, contrast tint you name it from one extreme settign to the other and nothing changes this effect. Brightness make it more prominamt than anything else. I have 285 hrs on my lamp so I am thinking it is not the lamp. I do have a new lamp I will change out and see if I can see the same effect tomorrow.


The source is a panasonic BD35 and I can also see it on HD TV but not near as bad but it is there. Is this some sort of PJ effect that is unwanted and can be calbriated out. I used HD esentials to do my first calibration and have been very happy up untill my last two movies watched.


It almost looks like burn in on the old projection tv's that yellow/green color.


Any help would be greatly appericiated.


Thanks

Phil
 

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If the banding is visible on uniform backgrounds (connect a computer to check), then your projector might be defective. If the effect appeared recently, it could be a burned blue polarizer. This is quite unlikely for a new projector. Still, have you had overheating shut-downs? If your projector had the color shift from the beginning but you just noticed it, then it might just be the usual LCD color shading - caused by imperfect panel installation. There are other possible causes, for example a source that can bet set to apply certain settings to half screen only (like ffdshow). Nicotine on the lense. Even lamps can cause color shift: color shift over lifetime or a shift by bulb deformation. Please post a picture.
 

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> can also see it on HD TV but not near as bad


Oops, overlooked that bit. In that case it is obviously not a hardware fault. Apparently something in Epson's image processing exaggerates it (skin tone option? video level setting?).
 

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Discussion Starter · #4 ·
Well here is the news, the replacement referbished PJ is by far louder than my original and still shows the same color problem in the exact same scenes so now what?


Is it a problem with the movie or the blu ray player or cabeling? I think not becasue when I switch from the PJ source on my 106" screen to the 50" panny plasma the same image that is paused does not show the color problem on the TV.


I am thinking that this may just be a limitation with the Epson 720 PJ and for what ever reason on certain movies that are probused and filmed in a certain light under certain conditions that this PJ doesn't like it. Maybe I am expecting too much from a 720P PJ or maybe it is something that I am missing.


I wish I knew if there was a proper name for what is going on I am sure there is. The best way to describe it is like this:


The image is of the back of a guys neck if you were to go close enough to the screen to see all the pixles the image of skin tone may be made up of 500-600 squares that can be seen. Out of those 100-200 squares are a distinct color differance that look greenish or yellowish. Now with that being said the image may change and in the same location the picture is fine within the same movie, there may be other skin tones in that same area and nothing.


I am drawing a blank on this one if any one can help that would be great but I do know the refirbished PJ is going back and I am keeping my original.


Thanks

Phil
 

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Sounds like a compression artefact (blocking artefact, caused when the movie was encoded) that is just made more obvious by the projector. Have you tried a different skin tone setting to see if it affects how much the blocks stand out? Does your source have configurable post-processing, specifically de-blocking, de-ringing and sharpness filters? If so, try different settings.
 

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Discussion Starter · #6 ·
Mirkok I have tried every setting that there was to play with on the PJ rangign from the min to the max and no changes at all. Skin tone and brightness settings at the two that most affect it but neither will take it away. The source is a Panny BD35 and I have not looked into what it offers for post processing but I will thanks.


Looks like everything is good with the PJ then.


Thanks

Phil
 

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Discussion Starter · #7 ·
Hey since you led me to the artefact problems I fould this "Cross Color occurs when the video decoder incorrectly interprets high-frequency luma information (brightness) to be chroma information (color), resulting in color being displayed where it shouldn't." If you coupled this with the blocking artefact this is exactly the problem I have been getting.


Thanks

Phil
 
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