I posted a while ago that my friend's new/first DLP projector made no rainbows when we tested it here making a 3 foot screen or so.

He had it setup at his place now but it took him a long time to figure out how to disable the stupid parental control on his playstation to be able to play a DVD, even while reading the instructions it was a nightmare and we eventually gave up.

Now that he figured out how to get DVDs to play on his playstation, he told me he sees massive flickering of red green and blue and that the image is not watchable at all. I said many people say they get used to the rainbow effect and he said there's no way he'd get used to what he's seeing. It almost sounds like it may be a major defect. I haven't seen it yet but will tomorrow, but I never saw the rainbow effect and the only time I saw a DLp was the few minutes on the 3 foot screen we made here.

So what exactly do rainbows look like so I know if it's the rainbow effect or a major malfunction when I go see it tomorrow? As I said he says it's not something he can imagine himself get used to, I think he said it was flashing between colors and brightnesses.

His projector is the BenQ MP522.

Thanks

I see rainbows,but only the next day after hours of watching my pj.The rainbows I see are when I look across the plant where I work and look towards the plant lights.They are best described as a complete circle of rainbows around the lights.My eys are tired and a little blury also.But it goes away after a half a day or so.It seems worse in the winter when the air is dry.

http://upload.wikimedia.org/wikipedia/commons/c/ca/DLP_rainbow_effect.JPG

What do you mean by look accross the plant lights? Do you have a lamp and plant in front of your projection screen??

And leeperry: What in the world is that?

Thanks

And leeperry: What in the world is that?

Thanks
It a picture of what the rainbow effect is. Though its a large exaggeration as its someone waving their hand in front of the lens, but its the same basic idea.

The best way I can describe it is that every really bright object in a scene has a flashing, prismatic "trail" to it. Any dark scene with candles in it would drive me insane.

What your friend is describing does sound like RBE. It won't really be a matter of "getting used to it" (that would have never happened); it's more that he will stop seeing the effect.

This is a perfect example of it: http://www.dietforum.net/balagee/projected/rainbow.html

However, my case is MUCH worse then that. What your friend is describing sounds like exactly what I see. Only option is to get a faster color wheel speed, or go LCD/SXRD/LCOS.

Also forgot to add, I can't find a specific rating for that projectors color weel speed, but I found on a different forum that somone said it was a 1x wheel. If thats the case, getting a 4x or 5x wheel projector might eliminate the problem your friend is seeing. I see very bad RBE on color wheel speeds up to 5x. I have not tested a 6x but I highly doubt it will make much of a difference.

Wanna see rainbows? Run the opening titles for Alien (the original) on a dlp.

The plant lights that I was refering to are where I work at.I work in a big warehouse.The lights have a rainbow around them in the morning after a long night of watching dlp pj.I have a cheap dlp pj and think it is a 2 speed color wheel.Back when I had a 4805 I do not recall seeing rbe.But the 4805 has a 5 or 6 speed wheel I think.

The 4806 has a 4x color wheel. It actually interested because I never saw the RBE with my first DLP projector, the 4805. Not even my second DLP, a HD70. I started seeing the RBE when I got the HD1000u. So just because you don't see it now does not mean you wont see it in the future. My advice is this, if you cant see it, dont look for it. I started noticing it after I heard about it and really started looking for it. Now its just automatic. I see it whenever I am watching DLP. Ignorance is bliss.:)

So if he's really seeing RBE should he return it or try to learn not to see them (still haven't gone to see it yet)?

The plant lights that I was refering to are where I work at.I work in a big warehouse.The lights have a rainbow around them in the morning after a long night of watching dlp pj.I have a cheap dlp pj and think it is a 2 speed color wheel.Back when I had a 4805 I do not recall seeing rbe.But the 4805 has a 5 or 6 speed wheel I think.
So you say you see rbe on warehouse lights after a night of watching dlp? Unless i am misunderstanding i say bs. Rbe is caused by a very different function.

So if he's really seeing RBE should he return it or try to learn not to see them (still haven't gone to see it yet)?

Well first of all, why would you get a buisness projector for movies? You can get a much better picture for the same price if you get a home theatre projector. You can not "learn" not to see the RBE. If you can see it then the DLP is not tricking your brain into seeing all the colors at one time. There are ways to lesson it like decreasing the picture size and lowering brightness, but if you see the RBE then you see the RBE. Nothing you can do about it.

You have no idea what I see.The only bs here is your post

He's not doubting what you're seeing, only saying that whatever it is isn't RBE, which is what the OP asked about.

RBE is most visible during dark scenes with small bright objects - if you scan your eyes back and forth across the screen quickly, you'll see the red, green, and blue segments individually in a "rainbow" as the projector is drawing each color on the screen. It is a VERY quick artifact, and has nothing to do with persisting visual phenomenon like what you are describing.

Obnoxious Red and Green flashes every time you blink or slightly turn your head. They also look like Green dollars falling out of your pocket, having wasted your cash on an RBE box.

For a more hands on example, buy a Mit HC1600 and find out.

Well first of all, why would you get a buisness projector for movies? You can get a much better picture for the same price if you get a home theatre projector. You can not "learn" not to see the RBE. If you can see it then the DLP is not tricking your brain into seeing all the colors at one time. There are ways to lesson it like decreasing the picture size and lowering brightness, but if you see the RBE then you see the RBE. Nothing you can do about it.

sorry. but i stopped seeing them within a few weeks with no changes to my setup at all.

BTW I forgot to say he's using it connected by composite video (the yellow RCA cable). Is it possible that the color wheel goes slower with this video input compared to when we tried it on my computer where we didn't see any rainbows (again, the screen was much smaller when we tested it on my PC)?

So should he return it, try it with a PC, or wait to see if he stops seeing them?

yeah composite is interlaced and the built-in deinterlacer is not too good......connect it to a PC before making up your mind, but the CW is prolly 2X so don't expect miracles :D

Here's the only kind of rainbow I like seeing, in this case a double rainbow - took this from my front porch 2 years ago, local paper published it.

http://lh3.ggpht.com/_FqTNmgNQHz8/SJIMScfP8uI/AAAAAAAACOE/5qQlPlNJmUI/s800/DoubleRainbow6-23-08%20Panaroma.jpg

yeah composite is interlaced and the built-in deinterlacer is not too good......connect it to a PC before making up your mind, but the CW is prolly 2X so don't expect miracles :D
So would composite increase the rainbow effect (and/or even slow down the color wheel)?

So would composite increase the rainbow effect (and/or even slow down the color wheel)?
No, it should have no effect on the RBE. As far as i know it still is operating at the same refresh rate, it just has to be passed through a deinterlacer first.

OK well I don't know where my friend is I haven't been able to contact him.

I've been putting off my purchase of the Sharp DT-510 to see his first but I don't know when I'll be able to get in contact with him. Should I get the DT-510 anyway without seeing his projector? As I said when it was doing a 3 foot screen from my computer even with high action videos we couldn't see RBE even when looking for it. The Sharp DT-510 has a 5x wheel.

The reason I want to buy the Sharp ASAP is my current projector just hit the 40% life left mark and I want to sell it before it hits 39% as 39% looks a lot worst than 40%.

So should I wait until I finally see his or risk getting the DT-510 which I can't return?

Thanks

Here's the only kind of rainbow I like seeing, in this case a double rainbow - took this from my front porch 2 years ago, local paper published it.
Not much going on in town ?:p

aab1, get the DT-510. You will not be disapointed. I see RBE with the 5x color wheel, but as I have said, I am very sensitive to it. It is watchable though. The DT-510 is a golden 720P projector but I would not pay more then $700 for it brand new. If you can find it for around that price jump on it. Those older higher-end 720P projectors are a dieing breed.;)

Well I was finally able to go see it. We put a movie with action and explosions against black backgrounds and barely saw rainbows at all while trying to see them. I'm now confident that the DT-510 will be great.

He did mention that the rainbows, or whatever he was seeing, got much worst at some times regardless of the action or even the same movie could be fine once and unwatchable another time. He also said once he saw a wide horizontal "rainbow" bar going accross the middle of the screen while there was nothing special about the middle of the screen.

Could it indeed be a defect in his projector? In any case as I said it was great when I went to see it today.

Thanks