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Discussion Starter · #1 ·
-Setup - JVC G11 modified by Mark Foster, HTPC with GeForce SDR 12.xx drivers, SB GamerX, Cel 800, 256 megs Ram running @ 100, Powerstrip 3.1 running 1360 X 768, and yes I have tweaked the pixel settings.

- I went from 98SE to Win 2K Prof., tried different drivers, OS's, etc. but still notice that the icons on the right side are razor sharp, and the icons on the left side are slightly blurry.

Any suggestions? Does it sound like I have a bad projector? Is it possible that the internal convergence is off?

Thanks in advance! - Mase
 

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I saw what Jason's projector is doing. I'm used to CRT - it looked exactly like convergence was off.


Sharp on one side of the screen, but as you moved across, red and green gradually became more and more out of convergence.


Is there a way to adjust convergence in a DILA? I didn't think so...
 

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You can use Dilard to adjust each of the panels in whole-pixel increments, but that sounds like it won't help you.


I have a similar problem, but in my case it's razor-sharp in the center but red deconverges towards the sides (ending up about 3/4 of a pixel off on each side). From 9' away it's invisible to me, and since I have exactly zero dead pixels I figured I'd not risk JVC servicing it and replacing the whole optical block -- and I'm not even sure if they would.
 

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Discussion Starter · #4 ·
Thanks in advance for all of the feedback.

I'll do the string test tonight or this weekend and report.
 

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mase,


This seem like a stupid question, but are you absolutely positive that the projector is perfectly aligned with the center of the screen?


I have seen as much as 1-2 inch off center being enough to cause an out-of-focus image on one side. As a test try pivoting the projector about it's vertical axis (moving the image left and right to see if the image becomes clearer or blurry). Any slight off-perpendicular projection can cause this, just as having the projector below or above the top or bottom edge of the screen (depending on if ceiling mount or table mount) can cause a less than sharp image at the top or bottom.


If this isn't the cause, then the projector would have to go in for service to have the RGB panels aligned on a jig for accuracy. Dilard will only correct for constant variations of RGB misalignment as you move across the projected image.


Brian


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Our Home Theater - http://www.fatbulldog.com

Last updated 6/1/01


[This message has been edited by brian_vh (edited 08-17-2001).]
 

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"and yes I have tweaked the pixel settings."


That did include the tracking, right?


What are you using to adjust tracking?


I can get that exact same scenario if my tracking is off by just 1 number.


Chris
 

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Quick way to check centering.


Take a thread and tape it to the bottom your DILA centered at the lense. Take the thread to the right side of your screen. Then hold it at the left side. Is it the same length? If not then you'll have to re-align your projector or live with the focus.
 

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I agree with Brian. Are the two diagonals of the projected image equal (you can use the no-signal (blue?) screen to subtract source effects)? If they are not, then that needs to be corrected first. Vince
 

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The easiest test for checking the focus of your projector is to select the Green background screen from the menu of your projector. Then go up to the screen and see if you can adjust the focus of the pixels so that they are all sharp from edge to edge on the screen. This method will eliminate any possibility of the source signal being a contributing factor to your focus issue.


The other possibility is that the lens itself may not be properly seated against the mounting point inside the projector. If a screw is loose and the lens is slightly skewed then this could definitely be the cause of your problem.
 

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Mase,


If you don't have Dilard, you must use Mark Rehjons "test pattern" for adjusting your tracking and pixel. For 1360 x 768, you're going to find that to be a tracking of 28 or 29 most likely.


If you can't find or don't have the test pattern, let me know. I'd be glad to send it to you.


Chris
 

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Discussion Starter · #11 ·
I did the string test. The screen is within 1/2 inch on each side.

I play with the pixel adjustments and think I may have corrected the problem, but my eyes were losing focus so I am not 100%.

I will look again this week and report.

Thanks for all the responses!
 

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For focus, look for the tiny dot in the center of each pixel. If you see these dots clearly, you're in focus. If you don't see the dots at all, adjust focus until you do! For uniform focus, these dots should appear in every pixel on the screen.
 

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Discussion Starter · #13 ·
Anson and Cclay thx. I do have Dilard and will try out the focus this week.
 

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Anson,


The dots in the centre of the pixels are a characteristic of DLP projectors. You don't see them on the D-ILA devices (like the G11). Mase is going to be disappointed if he starts looking for them!


Regards,


Kam Fung
 

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Here's an interesting twist on this.


I just recently ceiling mounted my Dukane 9000D (G10 clone) and did a lot of adjusting last night. I have the top of the screen at the same height as the top of the image exiting the lens. The image is properly centered on the screen and things are focused but I'm getting quite a bit of pincusion distortion at the bottom of the screen.


The top of the image is horizontally straight but the bottom has a noticable bow in it. Also the left side of the image is not vertically straight but tilts to the right by an inch or two at the top. I also have quite a bit or red shift/shading at this top left portion. The screen is prefectly flat and vertically and horizontally aligned. I'm fully zoomed in since I have a throw distance of 16 feet. When I zoom out the image loses the bowing at the bottom. I haven't checked if the vertical tilt goes away.


Since this is a G10 clone, it does not have the adjustment screw for ceiling mounting. I'm beginning to think that either my lens has a defect or my D-ILA panels are misaligned. Are there any adjustments that can be done without opening the D-ILA up or should I send it in for warranty service?


Thanks for any help..


-- John
 

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Quote:
Originally posted by ghibliss:

The other possibility is that the lens itself may not be properly seated against the mounting point inside the projector. If a screw is loose and the lens is slightly skewed then this could definitely be the cause of your problem.[/b]
I also have a similar problem albeit not with focus but convergence drift, on my G-11. Can either the non-centered projector or the above quote cause what I am seeing? I get green contouring delineations and red ones on bright images at the left side of my screen. The right side seems ok. Could somethin g be loose inside the projector to cause a sub-optimal light path across the three chips?


Anyone notice?


Thanks,

Luca


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PICTURES OF MY THEATER
albums.photopoint.com/j/AlbumIndex?u=1659592&a=12715694&f=0
 

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Discussion Starter · #19 ·
This is the same problem that I have been talking about. Some of my theater friends think it may be a defect with my G11. It is slightly noticeable when the Windows desktop is displayed, unnoticeable when a movie is playing.


Another possibility is the Mark Foster mods could have thrown off the timing of my Visiontek GeForce card (to his credit he re-worked the mods several times to get things to work properly).


I have a Radeon 8500 on order from Dell ($199 use and abuse) and am interested to see if this fixes the problem.
 

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Luca,


Can you go into a little more depth on the problem that you are having? I'm having a hard time visualizing what you are seeing.


From the sound of it, I doubt that the new video card will fix the problem, though I would like to hear a more in depth description before I give me opinion.


Brian


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Our Home Theater - http://www.fatbulldog.com

Last updated 6/1/01
 
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