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Discussion Starter · #1 ·
I am starting a new thread for this because I am not sure if this is a flaw with my projector, normal for the projector, or an issue with the way I have set it up. I have a ceiling mounted pt-ax100 and am using almost all of the vetical lens shift (though this problem still exists when the lens shift is centered). I have a 120" screen. I have used the projector before finishing my HT but I am doing final setup now and have noticed something. As I said I am using a lot of vertical lens shift (very little horizontal). Anyhow I was leveling the projector and squaring up the corners and I notices that the image bows up at the center in the bottom half of the screen. I have attached a picture that illustrates with the test pattern. The projector is leveled and I have no keystoning as a result. While watching a 2.35:1 aspect ratio movie I noticed the horizontal line where the movie ends and the white screen begins was bowed up (curved) at the center. The top half of the screen looks fine with perfectly straight line.


Is this something I can correct with my setup? Is it a problem with the projectors optics? Is there and adjustment for this in the service menu? Can this be adjusted internally in the PJ by a service tech?


thanks,

Brendin
 

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I understand that the projector is level left to right - is it level front to back - is the wall plumb?


I'm going to guess it is an optical issue, though not necessarily a problem, just a possible weakness in the lens design.


Can you orient the projector in such a way that the bowing goes away - change zoom, focus, tilt front/back and left/right?
 

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Discussion Starter · #6 ·

Quote:
Originally Posted by Cyrano /forum/post/0


A bow at the bottom means it needs to aim lower. Raise PJ, lower screen or use keystoning to correct. Or any combination of the aforementioned.

Thanks...I'll play with it some more...the vertical sides of the projected image are parallel with the sides of the screen. The bow is on the bottom horizontal edge of the screen. I'm definitely not a pro when it comes to setting things up so I will keep playing with it. Did you take a look at the picture I attached? Just want to make sure that we are talking about the same thing. I appreciate your response.


thanks,

Brendin
 

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With the picture being from the angle it's shot from instead of direct head-on, it's virtually impossible for anyone to tell what's going on. Any chance you could get a real shot of the screen so we could take a look?
 

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Discussion Starter · #8 ·

Quote:
Originally Posted by Wilson-Flyer /forum/post/0


With the picture being from the angle it's shot from instead of direct head-on, it's virtually for anyone to tell what's going on. Any chance you could get a real shot of the screen so we could take a look?


you are right I'll post a better picture tonight. But just imagine all 4 corners are square to the screen and the left, right and upper edges are aligned with the edges of the screen where it goes to black. The only problem is the bottom of the screen bows up in the center maybe 1/2 to 3/4" from the black bottom bar of the screen. I tried it on the wall and same thing. If you look down the line similar to what I have pictured you can see it curves up a bit in the center. Kind of like looking down a 2x4 to see if it is straight or warped.


Brendin
 

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Quote:
Originally Posted by xnaron /forum/post/0


you are right I'll post a better picture tonight. But just imagine all 4 corners are square to the screen and the left, right and upper edges are aligned with the edges of the screen where it goes to black. The only problem is the bottom of the screen bows up in the center maybe 1/2 to 3/4" from the black bottom bar of the screen. I tried it on the wall and same thing. If you look down the line similar to what I have pictured you can see it curves up a bit in the center. Kind of like looking down a 2x4 to see if it is straight or warped.


Brendin

It really does sound as though the PJ is not pointed down enough. But it is an easy thing to check, especially if the wall is used.


Although if the PJ is level and the wall is level (plumb), pointing the PJ down more shouldn't be necessary. But you can try all possible solutions with an entire wall to adjust on.


Good luck
 
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