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3LCD misalignment (1 Viewer)

jmdanna

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Jacob D'Anna
I just got a Panasonic PT-AX100U from eBay and set it up. Once I went to focus it, I realized it wasn't focusing all of the way. I came close to the screen and noticed the red and green were offset a little left to right. Up and down is fine. See these pictures.
IMG_0838_zps8bf717d6.jpg

IMG_0839_zps66c15c30.jpg


This is highly zoomed up on my camera. From a distance, it's harder to tell, but I think the image could be sharper if this was aligned properly. Is there any way for me to do this myself? Or will I have to deal with it?
 

Steve Tannehill

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Belated welcome to HTF, Jacob!

It looks like your convergence still needs adjustment. I'm not sure how to do this.
 

jmdanna

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I think that is to move the entire image. So is it worth trying to take apart? Is it even possible to adjust the screens to have proper convergence? What would I be moving exactly? The LCD panels? Mirrors? Polarizers?
 

Mark-P

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LCD panels in projectors cannot be adjusted. The three-panel array is permanently cemented together at the factory. The manufacturing tolerance usually allows for alignment to be off by as much as 1/2 a pixel at the edges of the picture. I can't really tell from the picture if Panasonic would consider that to be in tolerance or not, but anyway since you bought the projector off ebay there's no warranty, so you'll just have to live with it. To have Panasonic replace the panel array would probably cost more than you paid for the projector.
 

jmdanna

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It looks like the red is one pixel off to the left. The two lines to the left of the top image are supposed to be one pixel width, but it shows up as two. I think the green and blue are combining okay, but the left panel is moved one pixel over and that results in the blue-ish green color to the right and the bright red to the left. I guess I'll deal with it, I could ask the eBay seller for a refund, but I need an LCD projector for the lens shift. My projector is not able to be placed in the center of the screen. And I have a feeling any used LCD projector i get will have some convergence issue.
 

schan1269

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Why not buy a 2nd one to compare it. Those are $400 all day long, $500 on Ebay. I found 3(within 3 hours drive) on Craigslist for $275-$400.

Then if the 2nd one does the same, re-sell it and you know it is a nature of the projector. If better, then ask for a refund/return from this seller.
 

Mark-P

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LCD projectors are seldom spot-on perfect with panel alignment. Mine is off a bit on the outer edges of the screen, but you can only see it if you get your face right up to the screen. If your red-panel alignment really is off by one whole pixel everywhere on the screen then that is kind of bad. Alignment is one of the drawbacks of LCD projectors. DLP projectors don't have that problem (at least not the single-panel DLPs).
 

GeorgeAB

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A few years back a manufacturer rep for Epson stated in a dealer training that at that time their standard factory tolerance allowed for pixel alignment was +/- an entire pixel. Epson makes all "3LCD" light engines used by themselves and other companies. I don't think Panasonic uses that light engine. All three-chip projector designs have the challenge of achieving tight RGB pixel alignment. Some of the newest Epson units offer digital multi-zone convergence adjustment, but due to the limitations of digital processing, can result in other image problems. Pixel misalignment produces a softer image, somewhat akin to chromatic aberration or other optics irregularities or weaknesses. As mentioned previously, single-chip DLP avoids pixel misalignment. This is one reason why I generally prefer that technology. I would not recommend trying to monkey around with the construction of your light engine. "DIY" can also mean "destroy it yourself."

Another way to soften your image and induce additional color fringing is to use lens shift to extremes. Spherical lenses are sharpest in their centers. As you increase lens shift away from dead center, consequences to image integrity are inevitable, except in very expensive optics that typically cost more than your entire projector when new.

Best regards and beautiful pictures,
G. Alan Brown, President
CinemaQuest, Inc.
A Lion AV Consultants affilate

"Advancing the art and science of electronic imaging"
 

jmdanna

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Okay something strange just happened, i think I may need to ask for a refund. I was putting in a movie to watch and when the screen was black, i noticed a couple spots show up on the screen. I put a piece of white paper up close to the projector and saw this.
IMG_0841_zps0ac80789.jpg


What happened? Return the projector?
 

schan1269

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Well...

Was this sold "as new", "as is" or "just a used projector"?

You didn't spend much for it.

I just checked completed listings. That projector, none of them sold in the last 90 days sold for more than $400.
 

jmdanna

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Used. I payed $400. Is this problem likely to get worse? I think I will have to return it.
 

jmdanna

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Jacob D'Anna
The seller is exchanging mine for another "good one" he has. Crossing my fingers!
 

jmdanna

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What are the chances that those dots on the screen would have gotten worse? Does anyone know what those are? Pieces of dust? Burnt spots in the LCD panels? I have no idea.
 

jmdanna

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Jacob D'Anna
New projector came, got some good and bad news.

Good first,
1. The convergence is Much better, and movies look quite a bit sharper.
2. The colored spots are gone. (still saw some spots on the white paper but nothing shows up on the screen)

Now a couple bad things
1. The left side of the screen turns a slight reddish color. (really only noticeable on a white or very bright screen)
2. After a couple minutes on a certain test pattern, the image became slightly burned into the screen. I saw it on the home menu on my Blu-ray player. It started fading immediately but to be sure I put on the pixel flipper on the Disney WOW disc for a couple minutes and it went away completely. I don't know why it was so easy to burn in like that, but I suppose it will be fine as long as I mainly just watch movies.

I'd rather not send this one back too. I wanna keep it, but someone reassure me. Is this thing gonna hold up? What are the chances of it getting worse?
 

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