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Hey there all,

I am new to much of this, but did do a lot of research before my purchase of the Benq W1070.  I had it side by side with an Epson 2030 and the DLP picture was far superior.  However, I am unfortunate that I see the dreaded "rainbow effect"...pretty significantly.

 

I have it ceiling mounted,

--I used ProjectorCentral's calculator and have it within the recommended throw distance,

--Throwing it to a 120" 'screen' (wall, that I intend to paint a neutral grey--don't want/can't spend the money on a screen right now),

--And I have done nothing to calibrate it.  I am using roughly out-of-the-box settings.  By the way, I am shocked at just how good those settings are and the quality of the picture overall.

 

My questions are:

1.  Can the rainbow effect be minimized in any way with something such as correct calibration? (or is that for color accuracy only)

2.  Do these DLP projectors have any settings that would effect the wheel speed and therefore amount of rainbow?

3.  Should I bother to purchase another DLP projector (such as the Optoma HD25-LV) and see if there is less of the rainbow effect?..or is it likely to be the same since it has the same technology?  I understand that the Benq may have a faster wheel, thus making it the best choice anyway.

4.  Is there any sub-$1000 DLP projector that is "known" to have the least amount of rainbow effect?

 

I understand some of the factors that can minimize it, such as less brightness and smaller image size, but I was wondering if I was overlooking anything.  

Sorry if I do not have the amount of knowledge that some may have, and I am in no way a video-phyle.  I just want as good a picture as I can get out of a sub-$1000 projector. 

 

If anyone should suggest calibration, could you also recommend best means of doing this.  I would like to be able to do it myself, if possible.

 

Thanks so much for taking the time to help and I look forward to any suggestions.

-Jim
 

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I have issues with RBE too and was a concern when buying my w1070 last week. When I first hooked it up I could see them right away. For me I changed the settings to cinema and lamp to Eco. This made them pretty much all disappear to me. Yes with certain scenes you can still see them but not bad. With the out if the box settings I can see them but still not bad enough to return. The only other DLP I have experience with a old Phillips rear projection and that was bad, not my set but inlaws.
 

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Definitely the RBE will lessen at the lower light output modes. It will also lessen as the bulb ages and dims. You could also go to a bigger screen but at 120 you are already pretty large.
 

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faster color wheel speeds help too. But now adays most single chip color wheel machines do not have variable speed wheels such as 5x, 6x, and 7x. Marantz projectors had such a user selection.
 

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^^ Mitsubishi uses a variable wheel, with their faster speed reserved for 24p signals only.


As to the OPs delimma, I'd recommend giving it time. Lowering brightness or turning on some ambient lighting that doesn't wash out the picture too much, might accellerate the process. But, if you're like most (most according to TI's research claims, and my own experiences), your brain will adjust. I think there's a sort of learning curve to teaching your brain how to process DLP. Unless you're one of the 10% (or whatever the statistic was of people who have a more serious reaction to dlp, which isn't just because of rainbows, but because of their vision and brain not being able to process the way the tech works), most ill effects of DLP tech should lesson as you acclimate.


I just switched back to DLP after around seven years with SXRD. The higher contrast levels of todays DLP projectors seemed to make rainbows even worse than the slower color wheel speeds of yesteryear. And needing a completely dark room makes RBE much more problematic for front projection owners than owners of conventional DLP displays.


I'd always been able to see rainbows, but you can learn to ignore them, just as you learn to ignore phosphor persistence and LCDs similar motion artifacting that I forget the name of. However, I'd never had as adverse a reaction to DLP as I did when switching back - in addition to seeing rainbows with every fade to black or scene eliciting rapid eye movement, considering I sit only about 1x screen width away, I'd get a headache within 30 minutes of watching. But you didn't mention headaches or anything so it doesn't sound like you're one of the minority who is more accutely affected by DLP tech.


I found games were actually better than movies at rainbows, despite the slower colorwheel speeds for 720p material and concluded that it had to be because of how I was watching. Gaming was a more focused viewing experience: I was engrossed in playing game itself, rather than studying the video as I'd learned to do from my time reviewing and is only natural for anyone to pay more attention to, when getting/evaluating/admiring a new display. But after a couple weeks of reminding myself that rainbows are more optical illusion than video anomaly, I could tell a difference. Wiithin a month, mabe two, they were all but gone, and now I also can game for long sessions without eye strain induced headaches, encouraging me to take a Goodies powder, if I want to keep watching/playing.


If you can see rainbows, you'll likely always be able to see them, if you want to. But at some point, you should reach a place where you'll actually have to actively "want" to, for them to be any kind of burden. People with more adverse reactions may not be so lucky, but in my experience, rainbows can be ignored almost to the point of obsolescence.
 

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The W1070's color wheel multiplier has been found to change depending on refresh rate.


We've found that it only runs at full 6x (technically it's a 3x mechanical wheel, but it has 6 segments, ie RGBRGB, yielding an effective 6x) when the input refresh rate is 50hz.


So if your source device (blu-ray player/HTPC/etc) offers you the ability to change output framerate, then up it to 50hz. More discussion about this here .


Since doing so my side, I'm hardly noticing rainbows anymore.


The other thing that's helped (as mentioned here) is reducing brightness: either by dropping to Eco mode, or by getting some hours on the lamp (since it naturally dims with use).
 
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Hi,

I just purchased a Benq W1070 to replace a very old Infocus X1. The image is projected on a white wall distance screen projector +- 110 inch, screen width 94 inch. This is the "old 3:4 screen" size for the X1 The white portion of the screen is surounded with a very dark blue paint to optimize contrast ratio. I use an old computer to play movie's, so resolution is set at 1360 x 768 @50Hz input VGA for now. The Benq W1070 is set at eco modus, calibrated with some settings i found online...projector is brand new so bare with me. Proper calibration will be done with the Avia calibration dvd. Once i digg up the Avia dvd.

So according to the projectorcentral calculation i am currently projecting @ 28 fL screen brightness. Nearly burning a hole in the wall :). Rainbow effect is very visible. My room is 18 feet long, 14 feet wide so there is lots of room for a bigger screen. I do like my movies bright, watch almost everything with subtitles (RBE!). And prefer a 30 degree viewing angle. I am comptemplating using the manual zoom on the Benq W1070 to make a Widescreen (1:85) / Cinemascope (2:39) screen. Fixed height 49 inch, width CS 118 inch, width WS 91 inch. After this long introduction, here is my question:

"Did anybody try to lower brightness by increasing the screensize and did this reduce the rainbow effect?"

(I do not like to paint the screen grey or use a polarization filter in front of the lens to reduce brightness, don't know why, seems like blasphemy to me. I am aware of the contradiction bigger screen more head movement, more RBE bigger screen less brightness, less RBE.)
 

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Hi,

I just purchased a Benq W1070 to replace a very old Infocus X1. The image is projected on a white wall distance screen projector +- 110 inch, screen width 94 inch. This is the "old 3:4 screen" size for the X1 The white portion of the screen is surounded with a very dark blue paint to optimize contrast ratio. I use an old computer to play movie's, so resolution is set at 1360 x 768 @50Hz input VGA for now. The Benq W1070 is set at eco modus, calibrated with some settings i found online...projector is brand new so bare with me. Proper calibration will be done with the Avia calibration dvd. Once i digg up the Avia dvd.

So according to the projectorcentral calculation i am currently projecting @ 28 fL screen brightness. Nearly burning a hole in the wall :). Rainbow effect is very visible. My room is 18 feet long, 14 feet wide so there is lots of room for a bigger screen. I do like my movies bright, watch almost everything with subtitles (RBE!). And prefer a 30 degree viewing angle. I am comptemplating using the manual zoom on the Benq W1070 to make a Widescreen (1:85) / Cinemascope (2:39) screen. Fixed height 49 inch, width CS 118 inch, width WS 91 inch. After this long introduction, here is my question:

"Did anybody try to lower brightness by increasing the screensize and did this reduce the rainbow effect?"

(I do not like to paint the screen grey or use a polarization filter in front of the lens to reduce brightness, don't know why, seems like blasphemy to me. I am aware of the contradiction bigger screen more head movement, more RBE bigger screen less brightness, less RBE.)
I have definitely noticed less RBE as bulb dims with age and when going to a larger screen. I have an Acer 9500 and I started with a 100 inch screen. The RBE was very noticeable to me, almost any time I moved my head or darted my eyes I could see it. As the bulb aged and dimmed it went away almost completely. I then went to a 120 inch screen and have replaced the bulb and the RBE was much less noticeable than with the 100 inch screen and a new bulb.
 

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Thanks! I will paint a bigger screen and report back! On a side note: would be wonderfull if all projectors came with the standard zoomrange to do at least 1.85 / 2.35 within one image height. Seems so logical... but it's really rare. Cinemascope imo should always be wider than Widescreen / 16:9.
 

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Some people are more sensitive to RBE than others: some can't stand to watch DLP images at all.
Some projectors are better at hiding it: multi-chip DLP projectors and those single-chip DLPs with high speed color filter discs.
Some scenes are more prone to it than others: vertical high-contrast edges tend to be the worst.
There is some anecdotal evidence that people get used to it and don't notice it as much after a while. This might be due to dimmer images, or because we don't notice things that we see often: we see what we expect to see, and not what's actually there.
 

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I'll throw another voice in for dimming the image with a bigger screen, darker screen (painted flat), or $15 NDfilter..along with eco mode, of course.

I'm not particularly RBE sensitive anymore, but I used to be during specific, fast night scenes. Even then I never had it bad, and now I'm part of the lucky supposed majority who can even watch a 2X Optoma without any trouble or distraction.

Because I've seen RBE and know what to look for, it's still easy enough to force myself to see it by twitching my eyes side-to-side rather than watching the image on screen. So I can loosely tell (at least by comparison) if one projector is showing more RBE than another even though I no longer experience RBE during normal viewing.

I recently painted a wall a very dark grey for a screen in a darkened cave/room and found out that I can't even FORCE myself to see RBE with my DLP on this dark screen. If I get my hands on a slower CW DLP sometime in the future I'll have to try it and report back.
But, yeah..if you're painting a neutral grey and can experiment a little, try going darker or do a search on avs for the recommended $15 NDfilter.
 

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Thanks for the answers

I am very sensitive for RBE, i have owned an Infocus X1 for many years, i know the sensitivity for RBE wears of. And know exactly when it will show. Although i am sensitive it's not a big problem, the big smile i get from the picture the Benq W1070 throws balances things of nicely.

On the other hand. I used to be a 35mm projectionist. So anything wrong with the picture sends PANIC sensations down the spine. That's something that will never wear off. Would be great if at least the subtitles would be RBE flash free. Hope to get there with a bigger screen. I am aware the Benq is not a Christie CP2210 digital cinema projector, i can compare them on a weekly base.

My cinema background makes it hard for me to lower gain on the screen or use a NP filter, call it rigid, stupid or irrational. I don't feel happy wasting projector light. That would be my last resort.
 

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The used market can be a very good source of superior DLP machines if you do not want or need 3D.
For instance the Planar PD8150 should sell around $1500, OEM bare lamps are $175 and the machine is superior in every other aspect of image from focus to color accuracy than any of the current single chip DLPs on the market under $5000. The only issue is if it fails, you probably won't be able to get it fixed.. Currently on ebay there is a Runco LS5 that is the same unit as the PD8150 but with the Runco name as well as a PD8150.. Neither one "Should" sell for more than $15-1800 both are over prices and the LS5 has been thought several auctions with the max bid less each time.. Just another option that would provide and image as good as if not better than your Christine at work.. Personally I do not see RB and no one has ever seen them on this projector or the previous Mitsubishi.
I
 

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Constant image height is not possible with the Benq W1070. Only when i would use an abnormal amount of keystone correction or make a manual projection tilt construction. Can't win em all. -edit- any one tried constant image height with a W1070? It's hot where i live, could be preventing me from seeing the obvious, on paper the lensshift does not prevent the image from expanding in one direction only. Image is not perpendicular to the lens.
 

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good,That's something that will never wear off. Would be great if at least the subtitles would be RBE flash free. Hope to get there with a bigger screen. I am aware the Benq is not a Christie CP2210 digital cinema projector,
i can compare them on a weekly base.thanks
 

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What about the BenQ W1400 or W1500

They have frame frame Interpolation.

Would frame Interpolation help reduce the rainbow effect?
 

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Doubtful. I wish I had frame interpolation on my projector, if only for 3D frame packed movies from Bluray. (or watching Blurays from my Xbox One which doesn't do FI even in 2D).
 

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My two cents.

I bought an Acer H6510BD, a projector with a 2X wheel speed, so if you are rainbow effect sensitive you will see TONS of it.

When I bought it I was worried about being rainbow effect sensitive, turned out that I´m prone to that effect, vould watch it easily on dark scenes, it was a little of a let down, however, after 3 monthsI said "EFF it, I no longer care if I see it", and, suddenly, almost stopped seeing rainbows, now I barely see any rainbows, well, mind also plays trick to us.

STOP WORRYING about the rainbows and it would help a little ;)
 

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Would be great if at least the subtitles would be RBE flash free.
I forget what I was watching the other day, but I thought it odd that the subtitles were in GREEN as opposed to WHITE. I doubt the choice of a primary color for subtitles had the DLP RBE in mind, but it does make them RBE-free.:D
 
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