3-Chip vs 1-Chip with RGB laser - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 19 Old 12-31-2017, 12:48 PM - Thread Starter
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3-Chip vs 1-Chip with RGB laser

Which one is technically better? 3-Chip or 1-Chip + LED/laser with a RGB PWM frequency as high as the DMD chip itself could handle?
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post #2 of 19 Old 12-31-2017, 05:40 PM
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I have never heard of a single chip DLP projector capable of producing a rainbow free image using one chip, regardless of what type of 'lamp'/light source it's using.

What's the motivation of your question? Are you looking for a specific performance aspect between the 2 suggested scenarios?

Another thing to note...manufacturers using led pulsing trying to equate to a certain color wheel speed have always failed in my opinion. led's have frequently been said to have the capability of a "40X" color wheel, but I can't find a projector that's ever done that. it's always like 6 or 8x color wheel equivalent, which is so annoying to me. maybe pulsing at a 40X rate would make the image too dim? i have no idea

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post #3 of 19 Old 12-31-2017, 06:29 PM
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Quote:
Originally Posted by 4891ttt View Post
Which one is technically better? 3-Chip or 1-Chip + LED/laser with a RGB PWM frequency as high as the DMD chip itself could handle?
I have always wondered about the light that falls on each micro-mirror while it is in motion from off-to-on. It seems like there would be some benefit to sharpness, contrast, something by only pulsing light on the mirrors while they are in the position you want and going dark on the light source while they are in an in-between state. That would be true whether single-chip or 3-chip, however.

Single-chip can never produce all three colors simultaneously, though, which is the obvious advantage to 3-chip DLP -- brighter and lack of RBE. The only disadvantage to 3-chip is cost and the alignment problems that any 3-chip technology has.
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post #4 of 19 Old 12-31-2017, 10:54 PM
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Originally Posted by dreamer View Post
I have always wondered about the light that falls on each micro-mirror while it is in motion from off-to-on. It seems like there would be some benefit to sharpness, contrast, something by only pulsing light on the mirrors while they are in the position you want and going dark on the light source while they are in an in-between state.
That would be pretty tough to do when some pixels are on while some are off and the light source normally lights up the whole chip. A light source that is dynamic can dim when none of the pixels are supposed to be on, but can't do much when only some of the pixels should be on.

I think there is a misconception by some that as a mirror moves between on and off it will cause a streak across the screen. It would without a lens, but with a lens the image plane of the chip is focussed on the screen, so a slightly different mirror angle shouldn't have much effect on where the light hits the screen, as long as it makes it to the screen.

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post #5 of 19 Old 01-01-2018, 09:22 AM - Thread Starter
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If the light source could be turned on and off as fast as (or faster than) the chip itself, would adding more chips be advantageous or disadvantageous?
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post #6 of 19 Old 01-01-2018, 03:04 PM - Thread Starter
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As you know, color wheel and RGB LED are the same concept, one is mechanical (spinning wheel) and the other is electrical (pulse width modulation (PWM) of red, green, and blue light). A single-chip DLP LED projector without PWM would be black and white.

Edit: This was a reply to a now deleted post.

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post #7 of 19 Old 01-02-2018, 12:40 PM - Thread Starter
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Quote:
Originally Posted by cbaseuser View Post
What's the motivation of your question? Are you looking for a specific performance aspect between the 2 suggested scenarios?
Can single-chip ever be as good as (or better than) 3-chip on paper?
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post #8 of 19 Old 01-02-2018, 04:23 PM
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Originally Posted by 4891ttt View Post
Can single-chip ever be as good as (or better than) 3-chip on paper?
The only way would for it to have 3x the pixels, and each laser individually address 1/3rd of the pixels. (so basically a 3 chip)
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post #9 of 19 Old 04-17-2019, 08:22 AM
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I've resurrected this thread because I did not want to start a new one.

The UST laser DLP projectors interest me, but I'm sensitive to rainbows. Are there any 3-chip laser DLP projectors, either short or regular throw, for home use?

Thanks.
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post #10 of 19 Old 04-17-2019, 08:40 AM
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Originally Posted by Herve View Post
I've resurrected this thread because I did not want to start a new one.

The UST laser DLP projectors interest me, but I'm sensitive to rainbows. Are there any 3-chip laser DLP projectors, either short or regular throw, for home use?

Thanks.
3 chip dlp projectors are extremely expensive and you'd have to go with the likes of Barco, DPI, etc - more pro-grade than consumer assuming you want 4k.

If recommend you try a fast cycling very low RBE hld led projector like the benq ht9060 before you drop that amount of money on a 3 chip. A lot of RBE sensitive people don't see any rainbows on the ht9060.
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post #11 of 19 Old 04-17-2019, 12:59 PM
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Even then, there are none which would be UST.

UST projectors have very big hurdles to overcome when it comes to making a perfectly sharp image. To add to that the very high expense (for whatever reason) of 3-chip DLP, would not make sense at this time.

I figure some day they will get 3-chip DLP dialed in at a price point which makes it competitive with other 3-chip technologies.

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post #12 of 19 Old 04-18-2019, 05:07 AM
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Originally Posted by AV_Integrated View Post
I figure some day they will get 3-chip DLP dialed in at a price point which makes it competitive with other 3-chip technologies.
Personally I find with RGB Laser / HLD RGB LED 3chip actually becomes more of a disadvantage that an advantage. Those techs can cycle so fast since ethey have no color wheel even the RBE sensitive usually don't see RBE, combine that with single chip sharpness and brightness of RGB Laser/HLD LED and there is little point to take the 3chip sharpness/alignment hit.

In other words I disagree with your statement as some of the solid state lightsources have eliminated the main benefits of 3chip for home theater.
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post #13 of 19 Old 04-18-2019, 06:59 AM
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I agree with @Ruined . One of the big advantages of single chip DLP has always been sharpness due to not having the convergence issues of 3-panel projectors never being able to have millions of pixels in perfect alignment. One of the weaknesses of DLP has been the color wheel producing RBE. So single chip DLP with solid state light source and no color wheel may be the sweet spot for DLP projector technology.
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post #14 of 19 Old 04-18-2019, 08:19 AM
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Originally Posted by Ruined View Post
3 chip dlp projectors are extremely expensive and you'd have to go with the likes of Barco, DPI, etc - more pro-grade than consumer assuming you want 4k.

If recommend you try a fast cycling very low RBE hld led projector like the benq ht9060 before you drop that amount of money on a 3 chip. A lot of RBE sensitive people don't see any rainbows on the ht9060.
Quote:
Originally Posted by AV_Integrated View Post
Even then, there are none which would be UST.

UST projectors have very big hurdles to overcome when it comes to making a perfectly sharp image. To add to that the very high expense (for whatever reason) of 3-chip DLP, would not make sense at this time.

I figure some day they will get 3-chip DLP dialed in at a price point which makes it competitive with other 3-chip technologies.
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Personally I find with RGB Laser / HLD RGB LED 3chip actually becomes more of a disadvantage that an advantage. Those techs can cycle so fast since ethey have no color wheel even the RBE sensitive usually don't see RBE, combine that with single chip sharpness and brightness of RGB Laser/HLD LED and there is little point to take the 3chip sharpness/alignment hit.

In other words I disagree with your statement as some of the solid state lightsources have eliminated the main benefits of 3chip for home theater.
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I agree with @Ruined . One of the big advantages of single chip DLP has always been sharpness due to not having the convergence issues of 3-panel projectors never being able to have millions of pixels in perfect alignment. One of the weaknesses of DLP has been the color wheel producing RBE. So single chip DLP with solid state light source and no color wheel may be the sweet spot for DLP projector technology.

Ever since we bought our RS1 over 10 years ago, I have been really "out of it" when it comes to the evolution of DLP projectors. Are you all saying that there are now single-chip DLP projectors that do not have a color wheel?

Thanks.
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post #15 of 19 Old 04-18-2019, 08:27 AM
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Originally Posted by Herve View Post
Ever since we bought our RS1 over 10 years ago, I have been really "out of it" when it comes to the evolution of DLP projectors. Are you all saying that there are now single-chip DLP projectors that do not have a color wheel?

Thanks.
Correct, the best by far currently being this specific model:
https://www.benq.com/en-us/projector...ma/ht9060.html

Instead of having a single light source + color wheel to generate RGB, it has three seperate R / G / B light sources that electronically cycle extremely fast and no colorwheel

This can happen now because LEDs can turn on and off instantly, and the electronic cycling is not bound by the motor speed and segment size limitations of the color wheel. Plus, using the new phosphor rod tech HLD LED is over twice as bright as older LED projectors. HLD LED is the best transition tech until rgb laser is more available/affordable.

Blue laser projectors still use a color wheel for the same reason lamp did - but once RGB Laser is more readily available, this form of laser also will be able to ditch the color wheel for same reason as HLD LED.

Last edited by Ruined; 04-18-2019 at 08:38 AM.
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post #16 of 19 Old 04-18-2019, 08:42 AM
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Originally Posted by Ruined View Post
Correct, the best currently being this one:
https://www.benq.com/en-us/projector...ma/ht9060.html

Instead of having a single light source + color wheel to generate RGB, it has three seperate light sources that electronically cycle extremely fast and no colorwheel
Thanks. I did not know that.

Does this mean that there can be no RBE while watching the 9060's image, or can the "cycling" cause it? (I assume that a single frame of a movie would still be made up of three very fast images emitted from this DLP, whereas that single frame would be emitted from say a JVC LCOS pj "all at once" from the instantaneous combination of three colored "filters", for lack of a better expression.)

Are there other, less expensive, no-color-wheel DLP projectors and, if so, what are they?

Thanks again.
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post #17 of 19 Old 04-18-2019, 08:54 AM
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Originally Posted by Herve View Post
Thanks. I did not know that.

Does this mean that there can be no RBE while watching the 9060's image, or can the "cycling" cause it? (I assume that a single frame of a movie would still be made up of three very fast images emitted from this DLP, whereas that single frame would be emitted from say a JVC LCOS pj "all at once" from the instantaneous combination of three colored "filters", for lack of a better expression.)

Are there other, less expensive, no-color-wheel DLP projectors and, if so, what are they?

Thanks again.
RBE is caused by when the color components don't cycle fast enough to trick your brain into thinking they are a full color frame

It is similar to like when your framerate is too low on a moving picture and you see it "stutter" instead of motion. As you know, once you get to a certain point your brain stops seeing individual frames and starts seeing motion.

The same applies to RBE, and the slower the colors cycle the more potential there is to see it. Via the electronic cycling method, the colors cycle around 3x faster than the fastest color wheel. Sort of like reducing the chance of seeing stuttering in motion when going from 20fps to 60fps, you also reduce RBE potential in a similar fashion.

Now just like those gamers that say 120fps is much smoother than 60fps, there are going to be the rare folks that still might notice RBE with a projector like the HT9060. But for the vast majority the cycling will be so fast that RBE will not be visible, and hence this is the best compromise of sharpness, rbe , and affordability.

In the 4k world there is not really any other projector that is both cheaper and also good as the ht9060 with no color wheel, though it can be gotten as a steal from benq direct refurbs when they have stock. This model had a prior model that was released half baked with incomplete firmware that even today is missing key features (didn't even have fast cycling enabled at launch) , and that model is therefore a bust.

In the 1080p world there are several very good - but now also out of production - projectors that have similar fast cycling tech but they aren't bright enough for HDR; examples like the Runco q750i, DPI Cine LED 1000, and Vivitek H9090. But these aren't great for modern 4k as they aren't bright enough since they don't use the hld tech.

They are working on a version of HLD LED for the smaller 4k 0.47" DMD and that should produce models available new under $3k in the near future. For now though picking up a refurbished benq ht9060 from benq direct when they get more in stock is your best bet for low cost.

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post #18 of 19 Old 04-18-2019, 09:50 AM
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I would be interested in seeing the 9060. I have yet to see a DLP single chip projector in which I don't see any RBE at all. It doesn't bug me, but I do notice it. I'm not complaining, but I would be interested in seeing something like the 9040.

It would not be correct to say that the lack of a color wheel would mean that there is NO chance for RBE issues for some people as people definitely do see RBE, and the 2x and 4x pixel shifters have more potential for RBE overall.

I'm not sure, at this point, that I agree with others that single chip models will deliver overall higher quality than 3-chip models. I think there are just some real world limitations at play. Much the same as TI isn't able to get 8 million pixels onto a single chip for consumer use, they are running into real world speed barriers with DLP and shifting the pixels around.

I have no expectation to see anything that matters in regards to 3-chip DLP anytime soon. I just continue to believe that it will prove to be the one without the technical limitations of RBE and the drop in light a single chip system always causes.

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post #19 of 19 Old 04-18-2019, 11:33 AM
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Originally Posted by AV_Integrated View Post
I would be interested in seeing the 9060. I have yet to see a DLP single chip projector in which I don't see any RBE at all. It doesn't bug me, but I do notice it. I'm not complaining, but I would be interested in seeing something like the 9040.

It would not be correct to say that the lack of a color wheel would mean that there is NO chance for RBE issues for some people as people definitely do see RBE, and the 2x and 4x pixel shifters have more potential for RBE overall.
Like the analogy I made above - some gamers feel that 60fps isn't smooth enough and 120fps is what is needed for true fluidity. But for most people, 60fps is super smooth.

This is the same thing, the colors cycle so fast on the ht9060 RBE isn't visible for most. There will be a small pocket I am sure that still can catch a glimpse of it but I don't see this as a valid reason to incur the sharpness loss and greater cost for the vast majority of people that won't see it. You will lose sharpness with 3 chip and the money spent for 3 chip could have been put into a better lens or some other pq improvement on a single chip.

Quote:
I'm not sure, at this point, that I agree with others that single chip models will deliver overall higher quality than 3-chip models. I think there are just some real world limitations at play. Much the same as TI isn't able to get 8 million pixels onto a single chip for consumer use, they are running into real world speed barriers with DLP and shifting the pixels around.

I have no expectation to see anything that matters in regards to 3-chip DLP anytime soon. I just continue to believe that it will prove to be the one without the technical limitations of RBE and the drop in light a single chip system always causes.
TI has been capable of delivering native consumer 4k @ 0.95" since the start IMO (it would be same density as the 0.66xpr) but have not because they did not want to infringe on their $$$ 1.38" DMD pro business. So they put out the 0.66 xpr in the meantime, but I'd be shocked if an 0.95" native 4k doesn't surface in the near future

Native 4k will be too dense for the 0.66" size , but this is sort of a moot point anyway... If you've been following the BenQ LK970 thread there is an owner of both the lk970 and rs4500 who compared them on a 180" screen and found the lk970 to be significantly sharper despite it being 1/3 of the price and a shifter. Having 3 chips puts projectors at a big sharprness disadvantage to the extent they can be outpaced by 0.66 shifting single chip projectors. That being the case I'd say the 0.66 does get the 4k job done for consumers... And an 0.95 native 4k single chip will probably blow out of the water in sharpness anything we've seen to date on a consumer unit.

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