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Discussion Starter · #1 ·
I do not see it myself but 2 of my friends do.I wish to purchase one soon and would prefer one that doesnt affect my guests.Also I just heard here in australia that davis has gone belly up is this true.

Much thanks in advance from Dennis downunder:)
 

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DLP is a great technology, it's the spinning color wheel that causes the rainbow problems. If LCD or rLCD (AKA LCOS, AKA D-ILA) used just one chip and a spinning color wheel to produce color, the same problem would result.


In fact, a company in "Home Theater Interiors" is developing a single chip LCOS ("D-ILA") with a color wheel. Bad idea, IMO, but it shows that it's not just DLP that may have the rainbow issues.


Three-chip DLP projectors are absolutely beautiful, and don't have any image artifacts that I can see. Unfortunately, they are really expensive (for some reason, they are a *lot* more than three times as expensive as a one-chip DLP).


I understand that the rainbow effect is minimized by the faster wheels, and the wheels with more segments, and the wheels with the spiral patterns. We are just starting to see projectors with some of these improvements, and the archimedes wheel is probably a few years away.


Anyway, I apologize if you already knew all of this. I just wanted to mention that there is nothing in the DMD chips (DLP) that cause rainbow...it's the color wheel that causes it.
 

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Sorry, Dennis,


How completely rude of me. I did understand what you were asking, and didn't even offer any suggestions.


I have heard that the new Sharp 9000 does better at getting rid of the rainbows, but quite a few people claimed that they could still see it (although it was much smaller).


I think that you will find that the newer (and more expensive) single-chip DLPs minimize the issue, but there will still be people who can see it without much problem. I'm one of the unlucky single-chip DLP owners who is very much bothered by the rainbow.


Have you seen the Sharp 9000?
 

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I'll agree with Mark -- the Sharp XV-Z9000U does minimize rainbow quite effectively with the 5x wheel, but it can still be slightly visible.


Why don't you see if you can find a shop with the 9000 and bring your friends and some favorite DVD's along? :)


When I auditioned the projector, I saw rainbows exactly twice:


1) On Pleasantville. I think black and white will be the most obvious for rainbow, because any color will stand out. Even so, it looked very good exept during a shot of a street at night -- the streetlights (bright sources on a black background) showed some minor rainbow.


2) On the THX OptiMode screen geometry test pattern (the one with the circle). This caused bizarre persistence-of-vision effects on a CRT projector, too, so I sorta write that one off.
 

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Discussion Starter · #5 ·
thanks guys this is starting to give me some insight into the problem.

Dennis
 

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Rainbow effect: it is a very personal matter, as some people are more sensitive and some are less.

About 20% of the population have a faster eye processor and are able to detect what we call "the rainbow effect"


I am definitely in that 20% portion, however with the newer types of color wheels I must say that I cannot see the rainbow effect any longer.

One example is the SIM2 Seleco HT 200 and HT 200 DM, which is basically the same projector except for the Dual Mode chip and the 6 segment color wheel.

I was able to test both and on the first one I could vividly see the rainbow effect, while on the HT 200 DM there was no way I could detect it. Even watching B/W pictures like Casablanca, where it is easier to notice this rainbow effect I wasn't able to see it.


I repeat that the sensitivity to this effect is personal, but I would truly recommend checking out this HT 200 DM, it could be a winner.
 

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Buialat, I am not disagreeing with you here. I am just curious. Where did you get your 20% figure? I would have thought this figure to be higher. I am very susceptible to rainbow.
 

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I had the opportunity to spend about an hour viewing the 9000 with DVD's and an OTA-HDTV signal. This was the first DLP projector I've watched that I didn't notice the rainbow effect. The picture quality was impressive and I felt that I finaly found a digital project that I could replace my 7" CRT with. However after about 15 minutes of viewing, I noticed a strange effect on my eyes. They started watering and felt fatigued. I'm wondering if I was noticing the rainbow effect(flickering)just below my noticeable vision level, but enough to effect my eyes. There is another dealer in the Metropolitan Detroit area that has one set up and I plan to visit them soon. I'm interested to see if I notice the same effect. It would be a shame to experience this again as up to that point, the projector was definitely a keeper.

Jack Syer
 

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Quote:
Originally posted by Pete
In general, the newer projectors that are using six-element color wheels do not exhibit rainbow for those sensative to the phenomenon.
That is not correct. For those who are minorly, or not at all sensitive to the rainbow, the 6 segment colour wheels put the nails in the coffin on that issue. However, for those of us who are very sensative, we can still see the rainbow effect, even on the newest projectors. :(

It is a shame really, I want a single chip DLP, but cannot be happy with the rainbow effect.
 

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I have not yet seen the Seleco 200HT DM, but I have read here repeated statements of visibility. Especially, considering people can see it on the sharp z9000, which has an even faster colour wheel, I can say that the rainbow issue has yet to be completely resolved.

Unless, you are going to say that this is all hearsay...which I cannot defend.


I see rainbows on all regular 3 or 4 segment DLP.
 

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Quote:
Originally posted by jsyer
However after about 15 minutes of viewing, I noticed a strange effect on my eyes. They started watering and felt fatigued. I'm wondering if I was noticing the rainbow effect(flickering)just below my noticeable vision level, but enough to effect my eyes. There is another dealer in the Metropolitan Detroit area that has one set up and I plan to visit them soon. I'm interested to see if I notice the same effect.
Remember to blink!! ;)


I'm only half kidding. I think that when peole audition projectors, they sometimes are so intent on scrutinizing the screen that they don't blink normally, and get fatigued. I watched quite a bit of the 9000 in a fairly casual setting, and noticed no problems. But, on a different occasion when I was looking very intently, I got a little fatigued. I don't think this was related to the specific projector, though. (I hope not, since I have one on order!!)
 

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On this issue of Davis, the division that made the projectors was sold to Dreamvision, so while Davis is gone, Dreamvision now has all of their equipment and technology and will continue to create new projectors based on Davis technology
 

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I and some friends have watched Z9000 and HT200DM, both using 6 segments colour wheel and faster rotating speed. It shows that the new technology has minimized the rainbow to a low level. I can see rainbow from LT150 occasionally but don't see it from both aforesaid projectors. If you are extremely sensitive to rainbow, you can still see it from these new projectors but not as much as that from projectors using RGB(W) colour wheel.
 

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I have seen the Sharp and owned the DM. They both exhibit rainbow equally in my Gladiator tests...it doesn't matter that the Sharp is a little faster.


Interestingly enough, the LT150 is the first machine I saw rainbow on--and what ruined dlp for me (after seeing 4-5 pjs).
 

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Can anyone enlighten me on this projector? I cannot seem to find anyone who has this projector yet I have read very good reviews on it. Unfortunately the only DLP projector that I've seen is the new Sharp 9000 unit, which apparently has very minimal rainbows. Since I have no experience with this issue I have no idea if I will be susceptible to it.


I currently have a Sony Vpl W400Q which I would like to upgrade with something with a better contrast ratio. Since I have an HTPC I want DVI which the Sharp 9000 doesn't have. Other than that, the 9000 seems to be a great machine. I must admit that it looked very good with the DirectTV HD input that he had feeding it. I am also considering the Sanyo 60ht unit and although I haven't seen it, I've heard that it is very close to the 9000 in quality.


Bob
 

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Rainbows again:rolleyes:


This is SO overdone...I have had many friends look at my DWIN and I have not heard one complaint, even when I told them what to look for.


Oh well, just means I get enjoy a great pj at a great price. I feel sorry for those who "see" the rainbows..what a shame.


GigEm
 
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