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Discussion Starter · #1 ·
Finally a few days ago I was able to use my Panasonic AE300 with a new Da-Lite HCMW screen.

I have read many reviews on this projectors and so many opinions about the "blacks", screendoor and smooth screen technology, scaling problems etc... But nobody really told what the real AE300 problem is.

Oh yes, I have heard from other AVS forum users mentioning the so-called "vertical banding" but many AE300 owners didn't notice it and said the artifact is "very subtle".


Well, I just can suggest you to watch the first 2 minutes on PANIC ROOM and you will see how distracting the "vertical banding" is and how the image can look awful. This scanline artifact appears on certain scenes and is not visible throughout the movie. Again put Panic Room on your dvd player and take a look at what the vertical banding can do to the opening of the movie.


I have a HTPC wired to the AE300 via a VGA cable. The projected image is 106" (diagonal) and my seating position is at 2x.


I'd like to know if these artifacts can be worked out and if they are present on the new SONY VPL-HS10.


Thanks

htpc_madness
 

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I do not see the vertical banding issue at all. I am going to try and reproduce this with information from Mulveling.


Has anyone with a Pan RP-82 and the AE-300 seen this issue? I dont use a HTPC.
 

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One point, LMCid:

The issue here is not vertical banding, it is an artifact that looks like horizontal scanlines (or a combing artifact), and it shows up only in areas of medium to medium-slow vertical movement that are medium to medium-light in color.

htpc_madness, unfortunatley I have felt the same way ever since I got my white screen. They are not subtle at all anymore and it is frequently breaking my concentration when I'm trying to watch an otherwise engrossing DVD.

I find it really interesting that RP82 owners don't seem to have this problem, and I would be thrilled if it turned out using a good dvd player through component cables eliminates the issue. This would point to a serious issue with the VGA/DVI input and would eliminate HTPC as a viable option for the ae300. Anyone out there have experience with artifacts on vga and no artifacts on component? Anyone see artifacts through component?

At this point I'd certainly be willing to tolerate some screendoor if it meant getting rid of those scanlines. Got to get them out of my life!
 

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Mulveling, I can also see the horizontal scanlines with my RP82. They are similar to the interlaced scanlines on my 36" Proscan interlaced TV at approximately 5X screenwidth distance, although they are not there all the time and they don't cover the whole screen. Even though they are not that bad (for me at least) I also wish we could get rid of them....where is Li-on when we need him? I have a couple of questions:


1- Has it been ruled out if the scanlines are related to the scaler?


2- Has anyone been able to do pixel perfect mapping with this PJ?
 

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Hi,


I repeated countless time that all LCD projectors (I saw) have this "scan-line effect in vertical motion". It doesn't matter what you feed the projector, pixel perfect or not. Try to see the picture before buying to see if it's a deal breaker problem.


Oh yeah the "vertical banding" is a whole different issue...


regards,


Li On
 

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Li On,


I do remember your previous posts on this artifact and I appreciate your input and experience.

I also remember you mentioning that you found the scanlines much less apparent on the PLV-Z1 than other LCDs. Would you say the scanlines you saw on the Z1 was more or less visible than the screendoor at your seating distance? I am very interested in this, since I find the scanline effect on the AE300 to be very visible and frequent at 2.2X screen widths. I am not sure I could even find a distance at which I don't see them anymore.


Mike U.
 

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Has anyone measured the frequency of the light source for the projectors or the rate of refresh the LCD panels are undergoing. I'm thinking the horizontal black lines during vertical motion tracking is a strobe effect which is most pronounced when the freq of your eyes going across the interpixel gaps matches a harmonic of the lamp frequency or panel refresh.


An interesting experiment would be to rapidly spin a slotted disc and see if you see strobe effects when the disc is illuminated by an LCD projector showing a white field. If you can see strobing, then we have the culprit in hand.
 

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One other note is that I am projecting on an 86" diag High Contrast Gray DaMat screen. It maybe that the artifact is just not as noticable with this material.


My main boggle with the projector now is the Fixed Pattern noise I can see in light colors like the sky or light mountain ranges (I assume this is projector specific so nothing against all AE300's on this). I didnt see the same patterns from the material when we put the HS-10 up on the scree just now so I know it's FPN and not the screen material.


Also are these scanlines even across the horizon or do they sometimes bend upwards or downwards on the ends?


Henry
 

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In the AE300 service menu, you can adjust the "flicker" on the individual RGB panels. I don't suppose that will make a difference to the scan line artifact?
 

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Quote:
Originally posted by Xander
In the AE300 service menu, you can adjust the "flicker" on the individual RGB panels. I don't suppose that will make a difference to the scan line artifact?
Hey, that sounds promising! Should be worth a shot. Anyone know how to get into the service menu?


Mike U.
 

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Quote:
Originally posted by mulveling
Hey, that sounds promising! Should be worth a shot. Anyone know how to get into the service menu?


Mike U.
I agree, it sounds promising indeed.


I found this in usenet doing a search for AE100 Service Menu:


"...you can access a hidden setup menu and some basic test cards (all red, all green, all blue, etc) by going into Options and holding Enter for a few seconds on the first one."


Hopefully it is the same for the AE300. I will try it tonight at home.
 

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Quote:
Originally posted by Li On
I repeated countless time that all LCD projectors (I saw) have this "scan-line effect in vertical motion".
Yes, I actually witnessed the same "scan-line effect in vertical motion" that the AE300 has Thanksgiving weekend on the Proxima X540 that I've been borrowing for months on and off from work. I had never noticed it before on this projector but while watching Harry Potter and the Sorcerer's Stone I was sitting a little closer than normal to the screen due to a full theater room of happy guests :) and there it was... more subtle than the AE300 but definitely visible. I can only assume that the reason it's more pronounced on the AE300 is because the smooth screen technology does such a great job at reducing screen door and it's the usual screen door grid that that helps hide this artifact. Maybe wrong but sounds logical.


With this said my wife did not notice this artifact on the AE300 but did comment that she could see screen door? After pinning her down on this we narrowed it down to fixed panel noise, which, I agreed I could also see in shots of the sky. So Henryg you are not alone. This is also why Darinp preferred the M20X picture over the AE300 especially on HD sources. On my 96"x54" blackout cloth screen at 1.5x back I found the scan-line effect to be noticeably less visible than when I had viewed it on a Da-Lite matte white screen at the same distance so I think the screen material has something to do with it.


One thing is for certain though. For my wife (who was very critical of the AE300 image) to not notice this artifact and for htpc_madness to open this thread with the opinions he voiced indicates this artifact is vastly different between projectors, people, viewing environments or some combination of all three.


Brent
 

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I adjusted the flicker on the individual RGB panels and it seems that the temporary horizontal scanlines were almost eliminated. They weren't that big of a deal for me before so I may not be the best person to judge this issue. Anyone else tried doing this? The procedure for going into the service menu for the AE100 works also for the AE300.
 

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It's still too early for me to draw conclusions, but


Wow.

This tweak really does seem to have a desireable effect. For sure, it does not eliminate the scanlines, but from my seating distance they are much much harder to find tonight. I'm hoping it's not just that my eyes are tired - I will have to look at it again tomorrow.


Thanks LMCid for finding the service menu trick!


Xander, you are my new personal hero until the scanline artifact re-emerges :D


This whole issue is probably related to what Guy Kuo said, but his explanation went a little over my head ;)


--

Mike U.
 

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mulveling - How did you find the correct setting for the flicker option? What values were they before and what are they now? I dont see the scanline artifact and Im hoping when I change this I can see the difference.


Thanks

Henry
 

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Quote:
Originally posted by Henryg
mulveling - How did you find the correct setting for the flicker option? What values were they before and what are they now? I dont see the scanline artifact and Im hoping when I change this I can see the difference.


Thanks

Henry
- First, enter the hidden menu as LMCid described.

- Of course, go to the last option (flicker) and you should see a medium blue test screen with scanlines (I'm assuming you got here anyways). These lines are not the scanline artifact we're talking about as they are static. They do kinda look like them, though.

- There are a total of 6 test screens, use the up/down arrows on remote to switch test screens. One set of red/green/blue screens is for "Desk" (table mounted pj I guess) and one set for "Ceiling". Don't know why there are different settings for ceiling and table mount modes...

- Use left/right arrows on remote to tweak the "flicker" value of each test screen. The goal here is to minimize the CRT-style flicker in each of these test screens. It helps if you are sensitive to such flicker (I can see it easily on 60Hz monitor or tube HDTVs). I coudn't really see the actual scanline artifact on these test screens as they were masked by the static "scanlines". Again, not totally sure why this tweak helps, but it probably has to do with Guy Kuo's explanation above.


- The values I ended up with were:

72 for both red and both blue panels

73 for both green panels


- IIRC, the blue values were initially set to 71, the reds were way off, something like 76/77, and the green was off by 1 or 2. But I'm going on memory here.


- One thing of note: I was able to almost completely remove flicker from the read and blue panels, but unable to do so for green. I had a choice for green: 72 gave me flicker in the [big] center of the image, and 73 gave me flicker on the near edges. So I chose 73. From my attempts to reproduce the scanline artifact on the desktop (which was previously VERY easy to do by just dragging a window of something at the appropriate speed), I was really having a difficult time seeing it in the [big] center of the image. I did see some of the artifact near the edges, but it also seemed more subtle than before the tweak. I'm guessing this is from the green panel I described above.


Not sure if you will see an improvement if you couldn't see the scanlines to begin with, but you never know - messing with the values too much in the wrong direction seemed to throw colors way way out of whack.

Anyways, could be cool stuff, this forum is awesome! Glad a lot of intelligent people contributed to this excellent thread. Thanks, guys!


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Mike U.
 

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I think that Guy Kuo might have nailed the problem. There is a strobing effect taking place, and I guess that it is the mechanism used to do the smooth screen technology stuff. This is why you can adjust the flicker.


If you go into the "service menu -> service mode" and set the screen to the individual R,G,B colors, and move you eyes slowly up (for celing mount and down for desk mount), you can get your eyes to sync with the scan lines. They appear to be about 2 pixels high. It is almost as if the projector is doing a CRT/DLP type thing with the LCD panels. Hopefully someone that knows more about this can explain better to us what is happening here.


As a side note, I have noticed a slight misalignment (?) problem on the left side of my screen where I can see horizontal almost-screendoor-like reddish lines (see attached picture). It only happens on the left side and it doesn't appear to be a convergance problem (judging by convergance patterns that I displayed from a special test program on my notebook). I will send it back to Japan this week coming for replacement. I might open it up and take some pictures of the insides before I ship it.
 

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Not that I'm a fan of LCD but Panic Room brings out the worst in digital display devices. My 17SF (DLP) showed tons of nasties on this movie. Lots of dithering, grain, noisy looking walls, ect. Most other dimmly lit films look pretty good on the 17SF. I need to see this DVD on a big CRT.
 

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In my opinion, this thread should be renamed "How to get rid of the (dreaded) horizontal scanline artifacts on the AE300".


I spent some more time today with my projector and I am confident enought to confirm what was said last night and today:


The horizontal scanlines on the AE300 are reduced substantially (to the point where I have to look for them) by doing the simple procedure described in detail in this thread. Yes!!!!!!


I just finished watching Toy Story II with my wife and two and a half year old kid and I couldn't believed my eyes. I spent an hour and a half without being bothered at all by this artifact. In my case it was never that bothersome really, however, by reading so much about it on this forum it was starting to become worse already. I can still see it, but as Li On has said repeatedly it is there on all LCD projectors.


Good job guys, thank you Mulveling, Xander, HenryG and Guy Kuo. Mr. Kuo, if you are reading this, could you please elaborate on the strobe light effect issue. I am especially interested in the interelationship (if any) between the frequency of the lamp and the panel refresh rate. It seemed to me before reading this that the frequency of the lamp is just to high to be detected by human sight. You also mentioned "the freq of your eyes going across the interpixel gaps matches a harmonic of the lamp frequency or panel refresh", could you please elaborate on this as well.
 
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