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Discussion Starter · #1 ·
I sent back my G-15 with the dead pixel and got another one. Unfortunately, within 10 minutes of operation, another dead pixel popped up in the center top of the screen. Fortunately, I am using the Quadscan Elite as a scaler, and by using the bottom portion of the 4:3 panel for 16:9, the pixel is off the top of the screen.


The picture through the Quadscan is quite good now that I have the scaler adjusted (which took some effort). My initial impression of this particular G-15 unit, though, is that its ability to resolve fine details is not quite as good as the first unit I had, regardless of whether I run it through the Quadscan or just from the progressive out of my DVD player. The first unit was so sharp it was awesome. With this unit, it's almost as if the picture is very, very slightly defocused, kind of like what you do to an LCD when you want to decrease the screen door. It is possible it's my imagination, but I don't think so. Adjusting the focus to the best possible focus does not entirely eliminate the problem.


Is there something that I could adjust or that might need adjustment by a trained tech? (Adjusting sharpness helps a teeny bit on the video input, but the computer input does not have a sharpness adjustment.) I know CRT's need to have their convergence adjusted, etc. Is there something similar with a DILA that might be off?


P.S. Having tried a number of projectors and having read about different experiences that people have had with the same projectors I have had, it seems pretty clear that different units of the same model of projector can be as different as people in the same family.


[This message has been edited by smitty (edited 07-04-2001).]
 

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Maybe panel misconvergence?


Though you're not using a HTPC, if you have a PC you're willing to move and a null-modem cable, you might want to try running Dilard's calibration suite on it, to see if you can at least get computer input looking razor-sharp.


Mark, the unregistered Dilard is fully-functional, except that you won't be able to save settings back to the projector, so it resets when it powers down, right?


(My G15 is going to preceed my HTPC by a month or so, but I'd still like to give it the Dilard calibration runthrough upon arrival just to make sure I'm happy with it -- so the above question is for my own edification, as well).


-Chris
 

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Discussion Starter · #3 ·
Is there some pattern on Avia that I might be able to look at to determine if the panel is misconverged or whatever? In checking out a few other films, I'm not sure if there is a problem, or whether the G-15 in combo with the Quadscan is good enough that what I'm seeing is deficiencies in the soure, similar to what you encounter when you first get a look at NTSC through a good RPTV that has good resolution.
 

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I don't own a D-ILA projector, but on a CRT you'd use a cross hatch pattern to check convergence (its a grid of white lines against a black background). Look at the white lines and see if they have any colored halos. If they do, the projector is out of convergence. I'm sure that Avia has this test pattern. Good Luck!


[This message has been edited by belmore (edited 07-05-2001).]
 

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Smitty, Ihad the same question some time ago. For me, when I used the calibration cross-hatch that is in the software on my scaler (Rock) I noticed that each fine line was borded by a red hue to the right, and a blue/green hue to the left.....like if the three panels where not converged exactly to display one whole WHITE line. I was told that this is a function of the three panels which were not aligned exactly by the factory. However, this should not in any major way affect the quality of image that our Dilas are capable of. Perhapse in theory it would be great if they converged exactly, but even the factory techs say it's an academic exercise because it's difficult to align and weld each panel and you wont be able to tell the difference while viewing regular programs.


Jaime
 

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I have a G11 with this same misconvergence problem.


I agree that this misconvergence is not an issue with video output but when using it with a HTPC in PC mode it is an irritant. I do a lot of computer work on the big screen and I had looked forward to the razor sharp graphics (as oppossed to using a CRT that hasn't just been converged.) Imagine my surprise when all the text has fringes around it due to the inherent misconvergence in a 3 panel product.


Notch 1 for DLP's. Only 1 chip if you can stand the colorwheel artifacts.


-- Dieter
 

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Discussion Starter · #7 ·
Dieter, did you talk to JVC about the problem and whether it was something they would fix?


Jaime, if I look at the cross hatch pattern and I don't see any coloring to the sides of the white lines, does that mean I don't have a problem with my panel convergence?
 

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Smitty, this is correct. When all three panels are aligned correctly you should not see any bleed over. Red/blue/green superimposed *exactly* make white....a single white bar/line. There are some Dila's that happen to have had it done right from factory, but more likely many are misconverged by a tad....but, I'm not worried as my current set up is short of awesome (only because I'm still waiting for the panamorph and greyhawk screen).


Jaime
 

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This is a bit off the topic, but how much can one expect to pay for the G15 at this time?


Thanks,


Jeff
 

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Jeff,


If you go to the AVS Store and search on "G15", you

will find that Alan currently offers the JVC G15

with a Crystal Image Scaler on sale for $11,849.


Greg



[This message has been edited by Morbius (edited 07-05-2001).]
 

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Smitty,


I didn't bother to find out if it could be fixed. I am almost certain that the answer will be that a slight misconvergence is almost impossible to avoid with a 3 chip design. Getting a projector with perfect convergence would seem to be a matter of just being lucky.


It isn't a real big deal to me as my characters seem to have a green fringe on the right hand side. Just an annoyance.


And Dilard can only fix the problem in half character increments which doesn't help me.


I just remember that I bought the thing for video and in that application it is simply spectacular.


-- Dieter
 

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Discussion Starter · #12 ·
Well, I did look at the crosshatch pattern on Avia, and I noticed that the right side of each line has a green halo, and the left side has a purple halo. I had to get within a few feet of the screen, however, to notice this, as it does not seem to be noticable from my seating position (which is 12' away from a 110" diaganol screen). From the seating position the bars look white.


This being the case, does this suggest that my perception that some things are not as sharp as I would expect is likely due to a flaw in the source (which is DVD at this point), which is exposed by the excellent resolution of a DILA?
 

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I've noticed the same thing with the AVIA test images. Is this something that can be adjusted with Dilard's Pixel Alignment Wizard?


------------------

DVI/HDCP makes your HDTV not ready
 

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Discussion Starter · #14 ·
OK, help me out here. I checked the crosshatch pattern on Avia (100IRE) with my G-15. On the right side of the screen, there is a green halo on the right side of the vertical white lines about 4 to 6 pixels wide. It's only somewhat green at the 5 to 6 pixel. On the left side of the line, there is a purple halo that is about two pixels wide. When you get over to the left side of the screen, there are still halos of the same size on the left and right sides of the vertical bars, respectively, but there are not really colored. They are more of a grayish of whitish color. The horizontal bars also have a blue halo, which is about 1 1/2 pixels wide.


The size of this misalignment, if that's what it is, seems fairly significant to me in terms of what others have seen on their units, and I also understand that it is higher than permitted by JVC specs. My dealer said the spec was no more than one pixel wide. Do you all agree that what I am seeing on my unit is not right? Is it likely that this is causing the softness/fuzziness of lettering and other small details that I think I am perceiving?
 

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Dieter, JHill,


Unfortunately, the Pixel Alignment Wizard only has integral pixel adjustments (entire pixels), so you may be 1/2 pixel off after adjustment and the correction can not be made electronically.


If you were 3/4 pixel off, you would adjust the panel 1 pixel the other direction to be 1/4 off. The highest you would have to remain off is 1/2 pixel.


Now, that's all fine in theory, but I am hearing that more and more folks have slight non-uniform misalignment across the image. For instance, 1/2 pixel to the left on the right, and 1/2 pixel to the right on the left. Make sense?


There is nothing that can be done about that electronically.
 

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too late..


[This message has been edited by kyrill (edited 07-06-2001).]
 

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Smitty,


A picture is worth a thousand words.

Do you have access to a digital camera so that we can see what you are talking about.


Also, I don't know about Avia (I have VE), but in addition to the white grid on a black background, you should look at the inverted image of a black grid on a white background as well.


-Dean.
 

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Smitty:


If you indeed have a panel misconvergence of 4-6 pixels, I would think you could get the optical block replaced for that. JVC replaced mine because of a misconvergence that wasn't as bad as that. However, their policy may be different since they already replaced your projector once...


- Dave
 

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Discussion Starter · #19 ·
Dean, I don't have a digital camera. Pretty soon that's going to be a necessity probably. I will check the inverted image on Avia, as it does have that.


Dave, I have not returned any unit to JVC yet. The dealer just swapped out the first one. I think I'll try the picture from the component input to see how it looks in comparison to the Quadscan.
 

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I had a customer in Colorado with a G15 that ssemd to be unfocused.(drifted if you will) It cost about $300 to get is realighned form the JVC service in CAlifornia..it has happened to him twice..


Regards,

JOhn
 
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