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Discussion Starter · #1 ·
... so I was in Magnolia A/V yesterday and was looking at the Samsung's and the Cineos.


I want to say that while actually facing these TVs, with eyes fixed, I doubt most people would have a huge rainbow issue (and most don't).


What I found so disturbing was the same thing I've noticed before: When you are talking to someone or turning away or back to the TV or whatever, the rainbow artifacts are there over and over again for me. :(


This is not a sometimes thing, it's an all-the-time thing and I think a lot more people experience this than experience the "direct-view rainbows problem."


I guess, for me, it's a dealbreaker because it is annoying to see that over and over and over. I think a lot of people put up with it anyway, in no samll part because they have just spent $4000 on their TV... But I do admit it is probably still a minority.


On a loosely-related aside, I still don't get the Cineos. The Samsung's picture was -- to my eyes -- better on every dimension of picture quality. I suppose you could jam your face closer to the Cineos due to reduced screendoor, but so many other problems with the Cineos crop up at those distances (horrid shadow detail for one), I'm lost to find that advantage.


I am an LCOS fan; have been for years. I'd buy the Samsung over the Philips every time. (Relevance to this post: The rainbows are every bit as bad on the Philips as the Samsung).


Mark
 

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I see them occasionaly and only when I turn away. I seem to see them less after calibration. Is that possible? Maybe it"s just in my head.
 

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Not only do I see rainbows with the Samsungs, more than with the NEC HT1000 PJ, it does not handle camera pans well. The occasional distraction of talking to someone or someone walking into the room causes your eyes to dart and generates the dreaded rainbows.


But there is a more subtle effect: the eye strain. I have been using the LCD RPTV and it is a real relief to watch this thing. When I watch the DLP PJ, it takes getting used to since I do not use it as much.


My next PJ may be a 1920x1080 bright LCD. I'll give up the contrast for the pleasant viewing of a 3 chip projection system, I rarely turn all the lights off anyway.
 

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I also see rainbows. More so on the Cineos. Why can't the dlp makers speed up the color wheel fast enough to eliminate this?
 

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Quote:
Originally posted by mnc
I also see rainbows. More so on the Cineos. Why can't the dlp makers speed up the color wheel fast enough to eliminate this?
It's not just the color wheel that has to be sped up, but also the mirrors on the DMD chip. Those mirrors can only move so fast. See:
http://www.dlp.com/dlp_technology/im...technology.pdf

starting about page 8 there is discussion of how the chip creates grayscale and sequential color of a single chip system. The mechanical switching time is about 15 microseconds (or was at the time that paper was written - it's likely quite a bit better by now).
 

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Mark,


Don't you know that when you are in the theater there is to be no distractions or conversations? :rolleyes:


I never saw rainbows until I had the Cineos for about a week. I don't see them directly either. Only when I look to and away from the set quickly. Honestly, I don't see what the big deal is.


If anyone wants to tempt whiplash while watching TV or has a severe nervous twitch with their head, a single chip solution may not be for you.


The 3 chip sets have a different potential for problems. We have seen this in the GW's and the Toshiba LCoS. That is mis-alignment of the panels. Tos swore up and down that there could be no drift once set and some of the owners found that not to be true. We will see further down the road with the LCDs if they drift or not.


I know that you are terribly unimpressed with the Cineos. I find that the tighter pixel pattern to be pretty important since I sit just over 9 feet from a 55" screen. The DLP is not as smooth and the pixelation with the movement is very distracting. The colors out of the Philips are far more natural, though that is subjective and settings can change everything. I would really like to see ISFed Philips and Sammy next to each other apples to apples.


What I will give you for now is shadow detail. I have a feeling that some SM adjustments might change that, but no one is doing any SM tweaks AFAIK. The Cineos owners need a umr or Arun type to dive in.
 

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Discussion Starter · #7 ·
"Don't you know that when you are in the theater there is to be no distractions or conversations?"


Barry, my home is not the theater. Sometimes, we are watching a game or a show and we are talking. Please forgive me. :)


"The 3 chip sets have a different potential for problems. "


Totally true. I don't need to get whiplash to have single-chip problems, however. It happens pretty naturally for me. Still, 3-chip can have issues.


" What I will give you for now is shadow detail. I have a feeling that some SM adjustments might change that, but no one is doing any SM tweaks AFAIK."


Maybe it can be fixed; not sure. On LCD, there is simply not enough raw contrast to work with to solve these problems in some cases and the raw contrast of the Cineos does not appear to be all that good (typical of LCOS). But there might be leverage; perhaps Philips will provide a good service manual at some point?


Mark
 

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Yes, those of us who see rainbows are just able to see them more readily, I believe. I took my Samsung DLP back after a week because parts of the image where completely covered by the rainbow effect, even when I tried to stare at the tv without moving my eyes. I saw few rainbows in Star Wars Clones, a few more in T3. If the amount I saw in these movies was the worst it got, I would have kept it. But when watching Vanilla Sky it was just unwatchable. The scene in the opening when it shows a TV in the bedroom with a dancer on it, I think in black and white, was one big rainbow effect as the camera panned across. The scene where Kurt Russell is standing before a window in the cell-- more rainbows. Also when I tried to watch Emeril on the food network: TERRIBLE rainbows, as he was wearing a white shirt with a black overcoat.


I decided that I am not willing to find out that a show or DVD I was looking forward to was unwatchable... and I know it is something I am more attuned to and not something really wrong with the TV. Two friends (and the salesman when I took it back) could not see the rainbows at all, even when I told them how to see them. But let me make it clear: I am not waving my head side to side, just watching TV normally. And like rogo above said, when you look away from the TV they are really bad. If you in the minority who see them excessively, you are just very unlucky and welcome to the Rainbow Coalition, not affiliated with Jesse Jackson. ;)


It has been suggested that you can train your eyes not to move as much, but I think I will just let my eyes do whatever they want which sometimes involves moving them and blinking. I have not ruled out RK surgery, lol, if it would make the rainbows go away. But maybe some eyeballs can see images faster, who knows... it looks like I will be waiting for some major advance in DLP technology to come along. I am eager to view the new model line, though, but I am not too optimistic.
 

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I had a Samsung HLM617W DLP set for about a month. I saw rainbows all the time. Watching movie credits was horrible. I found that after watching the set for about an hour, I had to leave the set for a while due to eye strain. I can't deal with color wheel sets. Needless to say, it went back to Tweeter.


I then purchased the Toshiba LCOS set (3 LCOS panels, no color wheel). What a pleasure to watch. No eyestrain what so ever. I suspect the 3 panel LCD RPTVs are also easy on the eyes.
 

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Quote:
Originally posted by kwolfman
I then purchased the Toshiba LCOS set (3 LCOS panels, no color wheel). What a pleasure to watch. No eyestrain what so ever. I suspect the 3 panel LCD RPTVs are also easy on the eyes.
Are you up to date on the Toshiba LCoS?
 

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Quote:
Originally posted by Jfalconsfan
But let me make it clear: I am not waving my head side to side, just watching TV normally. And like rogo above said, when you look away from the TV they are really bad. If you in the minority who see them excessively, you are just very unlucky and welcome to the Rainbow Coalition, not affiliated with Jesse Jackson. ;)
Wow, that's amazing! Now I understand some of the complaints. I see the rainbows all the time when watching my sammy, but only when I dart my eyes toward or away from the set when there is a sharply defined white on black object. I really can't see them when I'm watching normally and sometimes have trouble seeing them even if I try. I think you hit on it when you mentioned how your eyes are moving even when you are staring at the screen. I suspect you dart your eyes about more than most. Very interesting.
 

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Quote:
Originally posted by Foxbat121
LoL! Wait until he found out what's the real deal with Toshiba LCoS sets:)
Okay folks, I know the Real Deal with the Toshiba LCOS sets. Mine went back to Toshiba this past Saturday. The point I wanted to make was that when it was working properly (it's first 6 months) the picture was unbelievably great. No fatigue watching that set.


There was just some flaw in the light engine that caused a degredation over time. Look at the two Toshiba LCOS threads for more info. It is not clear whether the LCOS panels themselves degraded or something else in the light path. Probably both.
 

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As I mentioned in another thread, I see rainbows in both DLP and the Phillips LCOS. However, with limited exposure, I don't find that the LCOS fatigues my eyes like the DLP did. Perhaps its the color wheel.


Does the scolling color technology of the single chip LCOS increase the effective refresh rate over a DLP/color wheel?
 

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Quote:
Originally posted by kwolfman
Look at the two Toshiba LCOS threads for more info. It is not clear whether the LCOS panels themselves degraded or something else in the light path. Probably both.
I'm very sorry Toshiba jumped ship. I was hoping a new improved model would have been ready for market instead of an "Ode to LCoS Lost" thread. :(
 

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Discussion Starter · #16 ·
Robbin, I'd say "sort of" in answer to your question.


With DLP it's Red - Spoke - Green - Spoke - Blue - Spoke (I may have the sequence wrong, but that's the idea).


With the Philips scrolling color, the screen is as follows:


RRGGBB

RGGBBR

GGBBRR

GBBRRG

BBRRGG

BRRGGB

RRGGBB


There may not even be any spoke time at all and the colors are rolling across the screen. What's odd, though, is that the color-separation, aka rainbows, is pretty darned similarly annoying.


Mark
 

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Quote:
I suspect you dart your eyes about more than most.
That's kind of what I was thinking, too. Too much caffeine, maybe! I tried watching from the stairs to get farther back since my den is kind of small, but I saw them just the same. I was thinking that if I were farther from the screen my eyes would not move as much...


When I first turned the set on, rainbows were so bad that I turned it off in disgust for two days... later I got into the tweaking mode and messed around with the settings and found that increasing the brightness made things much better, but only to a point. I too experienced some eye fatigue, but I think that went away with raising the brightness.


One other thing: I had heard about rainbows a long time ago but had totally forgotten them when I saw that first one, watching Aliens on VHS at the time since the DVD player had not arrived the same day as the TV.


I am so disappointed right now because otherwise it was a great tv and I want one. I see some rainbow-type effects in LCOS, so for me it will be a race to see which technology solves the issue first, if they ever do. (With so few of us around that are so bothered by it as to make it unwatchable, they may not have a good reason to ever solve the issue!)


Let me ask this question: is it possible a 7 segment color wheel can improve on the rainbow issue? I know it is mainly to help the blacks out, but I am just hoping it may cut down on rainbows enough that I will not be so bothered by them.
 

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Discussion Starter · #18 ·
Jeff, I dunno. I will say I've demoed the Sharp and Marantz projectors with the 7-segment wheel and didn't seem to suffer much rainbowing.... On the other hand, I've suffered it a lot with the 6-segment wheel projectors....


But the test data is pretty incomplete -- even for me alone.
 

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I personally find the rainbows very distracting - I think I am one of the "darting eyes" kinds of people :(


At CES when we were checking out the DLP's, we were always checking to see the rainbows - some were worse than others. The Philips LCoS didn't seem any better to me in the rainbow sense.


The wierdest thing was that I seemed to get rainbow burn in in my brain - after a while I could see rainbows on real things like walls and people...!


Anyways, all things considered my personal vote is definitely for 3 panel - even not so great convergence doesn't irk as much as the rainbow edges with those white on black scenes...


Cheers!

DAve.
 

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The wierdest thing was that I seemed to get rainbow burn in in my brain - after a while I could see rainbows on real things like walls and people...!


I have the same problem, I see rainbows on other things for about a good half hour after watching a movie on my Samsung hln567w, its wierd. Sadly to say this set is going back Thursday, I will wait for to see if they fix this issue.


Joe V
 
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