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Discussion Starter #1
Hi,


If you read my other recent post, you knew I'm VERY impressed by the little LT150.


Last night I finally set it up in my hometheater. I placed it just under my current CRT projector a NEC XG85. The LT150 projects the exact 84" 4:3 image at the same distance of the XG85. For a DLP projector, the throw distance is very short. And I like that.


DVD player Panasonic RA71, Video processor iScan Plus v2 480p component progressive. After checked a few discs and some adjustment, the picture is excellent.


Gamma - Natural 2 (normal too green/ natural 1 too dark)

Brightness - around 4 clicks below mid-point

Contrast - around 10 clicks above mid-point

Color - way below mid-point, only around 25% of the whole bar

White Balance - R brightness 3 clicks below mid-point

R contrast 5 clicks below mid-point

G contrast 5 clicks above mid-point

others at defualt mid-point


My screen is a 84" diag 4:3 Vutec 1.5 gain framed screen.


The resulting picture looked almost as great as the XG85. Of course the XG85 has a WAY BETTER black level but IMO the LT150 black level is still acceptable. Shadow detail is very close to the XG85 which is excellent. Resolution is excellent. As the LT150 looked much sharper than the XG85, sometimes the fine detail just looked more 'pop-out'. Excellent! http://www.avsforum.com/ubb/smile.gif In my setup the white level is just about prefect just like the XG85. NO white booming. Different layer of white layers resolved clearly. No problemo!


The more discs I check, the more I love the LT150 color rendering. The color layers is VERY accurate and looked really close to the XG85. Only the bright red is not as vivid as the XG85. The color really get me surprise! I never relies a single-clip DLP projector can give such smooth and rich color under all layers of brightness. All the LCD/DLP projector I saw can never get the color right.


And yes, with only 480p as the source, there're TONS of scaling artifacts due to the internal scaling of the LT150 to it's native 1024x768 panel. But the picture is still very watchable. The LT150 was used with a Faroudja NRS at 1024x768 the other night at TK Chan's setup and the picture was stunning. A HTPC should do as well.


Then I tried some HDTV source at 1080i. All picture control is the same except the Color setting need to return to mid-point default value. With only 1024x576 (16x9 in 1024x768), the picture is VERY high resolution and detail. Color is excellent. The picture is WAY sharper than the XG85! It's just a GREAT picture! Too bad if I looked REAL close, scaling artifacts is still there, just to a much lesser degree.


All in all, the best DLP projector I've even seen. Given a choice now with the XG85 or the LT150, I might just get the DLP to save all those trouble with a great picture to boot!

http://www.avsforum.com/ubb/smile.gif http://www.avsforum.com/ubb/smile.gif


regards,


Li On


PS: thanks to AVSForum and all the members talking about the great LT150. Thanks! http://www.avsforum.com/ubb/smile.gif



[This message has been edited by Li On (edited 08-27-2001).]
 

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Li,


Nice to see a post from a CRT owner who has done a head to head shootout between the LT150 and a good CRT! Try posting this at the CRT section of this forum and then run for the hills or at least make sure your life insurance is up-to-date!


There is a huge bias on this forum against presentation projectors, digital projectors in general, against projectors with low light output, LCDs because of pixelization and so on - to bad. Life is about learning and even if you think you won't like something sometimes you get a surprise - the LT150 was one of those surprises for me. Having a look at whatever I can demo is fun. We miss a lot in life by not keeping an open mind and by making assumptions! It's convenient, but hardly fair.


I am going to experiment with your settings, just to see.


There seems to be a a huge discrepancy in image quality some members see using the same projector. Some of this might have to do with the set up and some with what they are used to. Reds that are too orange, yellows too green, no black, no contrast, etc. etc. Luckily for me I am seeing what you are seeing.


Great post (of course I am biased)!


Cheers,


Grant

 

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What kind of screen are you using Li On? Oh and you really should try the HTPC to see what the LT150 is capable of.


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/frode
 

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Sorry Grant, but I am a CRT owner who has dome several head-to-head comparisons between DLP/DILA and CRT video.


IMHO the scaling artifacts that were mentioned earlier in this post make the current DLP technologies DOA in my house. These artifacts are typically more than just distracting, they are fatal.


With my current setup, 480p DVD and 1080i HDTV are rendered beautifully with virtually NO artifacts. Although some folks will atempt to mitigate these artifacts with some outboard scaler or HTPC, they will still be there.


I certainly long for the sharpness of the newer digital projection devices, however based on what I've seen recently they are a long way off before they replace my venerable CRT.


 

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briandx, If you are disturbed by scaling artifacts, you may find comfort with the new 848x600 DMD DLP. At 848x480, scaling artifacts should be reduced to minimum.
 

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Quote:
Although some folks will atempt to mitigate these artifacts with some outboard scaler or HTPC, they will still be there.
Hmmm. Not sure "mitigate" is the right term. How about "eliminate" instead. When feeding native rez to my LT150 with a Geforce or Radeon I see no "artifacts". So I have to disagree with the "they will still be there" part.

And I get just as much improvement with my CRT image when using the HTPC as I do with either my DLP or DILA.


While there are issues with DLP I don't think "artifacts" has to be one of them.


Bob Wood



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~ The Sultan of Cheap ~
 

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I see a lot scaling artifacts when using a 480I or 480P source, including direct from a progressive-scan DVD player. With my HTPC they are really completely eliminated. Any artifacts at this point are coming from the HTPC, not the projector. I have some real "issues" with the LT150, but scaling is not one of them when using the HTPC.
 

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Li On,


I'm curious what the subjective difference in brightnes is between the LT150 and the XG85.


Thanks


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Noah
 

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Discussion Starter #10
Hi,


Thanks for all the kind words. http://www.avsforum.com/ubb/smile.gif


Now I'm cool down a bit, more afterthought.


Brightness level between XG85 and LT150. At total light off, the LT150 is around 10% brighter. When the light turn on, the LT150 is around 30% brighter than the XG85. The LT150 is much watchable when light on. When light off, the brightness level looks close. That is based on video playback value. The LT150 can be MUCH brighter if you push contrast and enable White Section.


Jim, I too have some REAL ISSUE with the LT150 after watch it 2 nights. Using 480p progressive input, I can understand that the poor LT150 internal scaling cause aliasing and stairstepping all over the image around object edge. But the problem is more than that.


There is a SERIOUS dithering and banding/polarization effect whenever there's panning/moment in the image. I searched the forum and found the issue was discussed before at http://www.avsforum.com/ubb/Forum10/HTML/007405.html and no solution was found yet.


I do believe it's the problem of the LT150 internal scaler. The other night when we tried the LT150 with a Faroudja NRS at 1024x768, the picture was beautiful without such problem.Tonight I'll bring the LT150 to a friend's place and try a HTPC with it. I believe that will solve the issue and I can live with that. As Jim said in the other thread, the LT150 must part with a device output native 1024x768. A progressive DVD player is no good.


The REAL ISSUE is HDTV playback! There is NO aliasing and stairstepping around object edge and image is VERY sharp and detail. BUT the dithering and banding/posterization effect is still there. This time it can be solved with a HTPC!


Someone please find a solution fast. Otherwise I'm dumping this projector! The problem is killing the LT150 fast IMO.


HELP! http://www.avsforum.com/ubb/frown.gif


regards,


Li On


PS: last night 4 friends came see the LT150 because I told them how great it looks. After a while, they all ask me this banding/polarization effect (in both DVD 480p and HD 1080i) and I don't know how to explain!


PPS: last night a friend took a few photo, I'll try to put them up later.
 

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Quote:
Originally posted by briandx:

Sorry Grant, but I am a CRT owner who has dome several head-to-head comparisons between DLP/DILA and CRT video.


IMHO the scaling artifacts that were mentioned earlier in this post make the current DLP technologies DOA in my house. These artifacts are typically more than just distracting, they are fatal.
That's true only if in your setup you're using the LT150's internal scaler. If, like most people who choose a business presentation DLP for home theater, you use an HTPC or outboard scaler, then the scaling artifacts are no different from what you see feeding a CRT from the same source.


I realize some people may not want to bother, but then again you have to realize that many people who do use an HTPC see an exceptional picture _without_ the scaling artifacts you complain of. -- Herb


 

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Discussion Starter #12
Hi,


Found another post about the similiar banding/posterization effect http://www.avsforum.com/ubb/Forum10/HTML/008436.html


Tonight I'll try the LT150 on a firend's HTPC (Radeon). If no such issue, then it's the LT150 internal scaler problem. Then the LT150 is only good for native rate to play DVD. NO GOOD for HDTV.


If the HTPC also show the problem, then maybe all single-clip DLP has the same problem. That means all 1-clip DLP can't be used for video playback!


regards,


Li On
 

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Unfortunately I now very much see the problem unlike when Kilgore first asked about it. It really only became visible to me after going to the hipower screen. Saw the problem with the screensaver of my Skyworth. Haven't really looked for it using the HTPC (it's currently doing a different duty). I think that if it really is motion induced as well then running in fullscreen (like the anime I've been watching lately) may make the problem worse and more visible. Will be doing some heavy duty ATI beta testing today so I won't be able to check unfortunately what kind of effect the HTPC has and I'm away tomorrow on a business trip.


It's possible that if Milori can come up with a way of updating the gamma tables on the LT150 then this dithering effect can be reduced, if not removed altogether. I also need to further tweak the gamma settings of my HTPC, and the brightness/contrast of the LT150. If you're not already using 60Hz on the HTPC I'd recommend you change to that as well.


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/frode
 

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Discussion Starter #14
Hi Frode,


I just tried my sub-notebook (Toshiba L1) to the LT150. The notebook has no DVD-ROM so I just run a few vobs file I ripped from discs with my desktop. The notebook CPU is too slow for WinDVD so I used PowerDVD instead.


Running in 1024x768 60hz fullscreen, the dithering and banding/polarization effect is MUCH reduced. But if I look close the problem is still there in some scene. Overall I think the problem is acceptable. But it should looks much better without the issue.


So, a HTPC for DVD playback is acceptable. Progressive DVD or just a line-doubler (iScan) is very bad. And HDTV is no good either.


There must be better way for LT150! http://www.avsforum.com/ubb/frown.gif


regards,


Li On
 

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Please point us to a movie scene in which this is very visible so we can all get on the same page.


Bob


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Bob - I won't be able to do anymore checks until the weekend at least if you want a scene to check it against. Are you sure you want to though? Remember ignorance is bliss http://www.avsforum.com/ubb/wink.gif .


I also have the added problem that most of my material is anime - not much live action. I currently only have 1 region 1 live action title - Hackers. The rest of my live action is PAL. Maybe I can check if VE exhibits this in the demo sequence. There's quite a lot of dark scenes there that may be good candidates. They're also full screen so that would help.


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/frode
 

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Yep I'm a masochist, frode, who wants to see all the defects. Better to see it now than first notice it while engrossed in watching a movie. http://www.avsforum.com/ubb/smile.gif

I do have VE.


An ideal comparison would be to find a movie scene in which it is particularly noticeable which is also a current HBO HD offering. That way we could compare it in 1080i, 480p and with our HTPC's.


Bob




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Discussion Starter #18
Hi,


2 photos of the XG85 and LT150 so you know I did tested the projector!

http://lion.telhope.com/~lion/temp/lt150/lt150-1.jpg
http://lion.telhope.com/~lion/temp/lt150/lt150-2.jpg


Tonight I tried the LT150 on a friend's HTPC with Radeon card, WinDVD 3.0 under 1024x768 60hz. The same dithering and banding is still there. After I pointed it out, the few friends at the gathering (including CKL) all saw the issue.


Then we just use ACDsee to viewing a large image (1600x1200 etc) and pan the image left/right or diagonal., and saw the same dithering and banding effect. Flesh tone is most easy to clearly see the problem.


Looks like it's a basic problem inside the DMD clip/circuit. If that's true, all 1-clip DLP projectors are screwed!


Now I'm REALLY unhappy with the LT150 no matter how much I like it's color rendering! http://www.avsforum.com/ubb/frown.gif


regards,


Li On
 

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Li On.....What's that tiny little grey thing next to that huge white whale? Wow I never realized what the size difference was. The LT150 looks to be 1/100th the volume of the XG85. Sorry you are unsatishfied with the LT150, but I am sure there are people who would like to take it off your hands.
 

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Quote:
Originally posted by Li On:
After I pointed it out, the few friends at the gathering (including CKL) all saw the issue.


Then we just use ACDsee to viewing a large image (1600x1200 etc) and pan the image left/right or diagonal., and saw the same dithering and banding effect. Flesh tone is most easy to clearly see the problem.


Looks like it's a basic problem inside the DMD clip/circuit. If that's true, all 1-clip DLP projectors are screwed!


Now I'm REALLY unhappy with the LT150 no matter how much I like it's color rendering! http://www.avsforum.com/ubb/frown.gif
I'm not sure, but from the sound of what you're describing you may be seeing the dithering/"feathering" artifacts that, you're right, are present in all single-chip DLPs. The artifact and the reason you get it is described in one of the TI whitepapers.


If this is what you're seeing, it seems a bit exaggerated to say "all DLPs are screwed." For one thing, many people are happily using their single-chip without ever having noticed it. For others who have noticed it (e.g., me), it's not something I can see from ordinary viewing distances.


I'm curious what your viewing distance is when you see this dithering. I can see the dithering/"feathering" easily on moving objects on my Compaq MP1600 only if I get up within a few feet of the screen. At normal viewing distances, I would never be able to see it. IMO, if you can see it at normal viewing distances, then either (1) we're talking about different artifacts, or (2) the feathering artifacs on the LT150 are for some reason easier to see than on some other single-chip DLPs. -- Herb
 
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