Any 3D projectors coming? - Page 2

Each LCOS engine has 3 chips in it - one for each color - RGB.

Yep - math is correct 24 into 360 = 15

The picture also clearly shows that the system uses circular polarization. It's especially worth noting that the 360fps switching means it's actually 3x faster than 240 LCD active shutter glass switching, such as you get with the Samsung LCD displays. With the Samsung, it's 120fps for each eye, but with the HDI system, it's 360fps for each eye, and both images are on the screen the whole time.

Again, my main problem is the 1,500:1 contrast ratio. I don't know how they're arriving at that number, but it doesn't sound good.

The Imax projectors do not put both images on the screen at the same time they display them sequentially.

Here is more complete descrition of IMAX projection then one in the Endgaget link:

"3D IMAX Technology
IMAX 3D technology is the most advanced 3D film technology in the world and is based on human vision. When you look at an object, each of your eyes sees a slightly different view. Through a process called "stereopsis" your brain brings the two views together into a single three dimensional image. The IMAX 3D projector uses Rolling Loop technology to run two separate rolls of film simultaneously past twin projection lenses. To enable the 3D effect, the lenses are carefully aligned to project both left and right eye views onto the giant screen. To see images in 3D, the audience wears either polarized glasses or a headset that includes electronic liquid-crystal shutter (E3D) glasses. While they have different technologies, both types of 3D glasses work with the IMAX 3D projector to provide stunning 3D images. Blockbuster IMAX Theater audiences wear E3D glasses. Two sets of shutters within the 3D projector switch back and forth at 96 times per second, to project alternate left and right eye images on the screen. During the presentation, E3D glasses sense a signal from the projector. In response to this signal, the left and right eye shutters in the glasses alternately open and close in conjunction with the projector shutters to make sure each eye sees the appropriate image, ultimately creating the 3D effect
"
The above is from the last paragraph of the following link:

http://www.mods.org/IMAX/experience.htm

I could be wrong, Lee, I don't think that's what the picture is saying. It says it projects 360 full frames per second for each RGB color, for a total of 1080 frames per second - x2, because both eye views are on the screen simultaneously. That sounds like DLP to me. It would also limit the number of LCOS chips the system would need to use - just two if each chip is handling only one color at a time.

Single LCOS chips would also mean no 3-chip convergence errors to be concerned about.

From the spec sheet:

Picture Brightness: 340 nits (100 Ft-L) Screen Gain = 1.6
Picture Contrast Ratio: 1500:1
Engine Lumen Output: 2400 - 4800 lumens

They are not doing the 6,000,000 to 1 game that the Asian CEMs play. That is probably actual CR. I remember during the 3 CRT FPTV days, 800 to 1 was considered outstanding

Aren't these the same LCOS engines used in the LG CF3D PJ? Those are 6 chips/dual engine design

For IMAX Digital they do. Here is an E-Mail sent to me from IMAX:

I'm hoping that number is an honest one, not the hyper-inflated, ridiculous contrast numbers we're seeing from so many manufacturers. It's still awfully low by today's standards. My main problems are: how far in the future before the sets ship, the chances of actually seeing one in person, and support when something goes wrong. There's no way I buy a $10,000-15,000 set without seeing it.

I don't know. I'm just basing my comments on what the picture seems to indicate. I interpret it as meaning they use only two LCOS chips. One of things they tout is how simple their design is compared to some of television's big guns - Sony, Samsung, Panasonic, etc. That's why it should be possible to sell the sets much cheaper with mass production.

They are selling them; "$10,000" in volume."

I emailed HDI about the low contrast number, but I never heard back from them. I don't fault them for that. They're tiny. But, they need to address such concerns at some point, or they'll never get any traction in the marketplace.

I read they will build you one for a cool $100,000. That might have been thrown out as a joke. The real question is, who's buying them at the $10,000 price and how much are they going to charge to sell them to us?

There are two ways to measure CR; Static and Dynamic.


http://www.practical-home-theater-gu...ast-ratio.html

When you look at all the FPD specs with the millions to 1 CR's they say; "Dynamic Contrast Range."

Big numbers sell

LOL - $100K?

You can buy a new Panasonic 103" PDP for $39K. They would probably sell you a 3D model for less than that from their truck tour - used of course.

The link I found described the IMAX film based system. I understand that the RealD theater digital system for display of IMAX provided 3D content uses a different method since these theaters such as my neighborhood digital theatre use a single projector.
What I don't understand is how an IMAX theatre film based sytem itself can project two separate polarized projectors at the same time on the same screen unless they are at different adjacent locations since I thought that a single location on a screen could not contain two different colors at the sasme time by using differrent polarizatrions. However, I umderstand from scarabaeus's post earlier today that it can be done or I misunderstood his post. Apprently IMAX has replaced the frame sequential polarized technique that was described in the link I provided or IMAX never used it at in their own theaters and my link is incorrect.

Still, JVC's latest DLA designs have native contrast ratios that measure in the 10s of thousands to 1, without a dynamic iris. That's the most troubling spec I see for the HDI laser system. Without actually seeing one, though, there's no way to see for yourself how the perceived contrast ratio and black level actually look. I'd consider taking a trip out to California to see one. I have a standing invitation from a couple of ex-students and their families to stay with them for a couple of days. I might decide not to intrude like that, but it would be a good chance to catch up with them. I haven't visited CA for a long time, and I could kill two birds with one stone that way.

The Engadget link on how IMAX 3D works is outdated. They have not used active shutter glasses for many years.

Current IMAX film 3D (real IMAX not digital lieMAX) works like this: 2 projectors are running simultaneously and show the left image and right image overlapping on screen at the exact same time. The images are separated using linear polarization through passive 3D glasses. The 3D system runs at 96Hz or "double flash" meaning each frame is shown twice before moving onto the next. When I refer to a frame I mean a left/right combo (1 frame out of 24fps of film) and is shown left image and right image, left image and right image, next frame and so on for IMAX (double flash).

RealD works using a single projector with a Z-Screen device attached in front of it. The system runs at 144Hz or "triple flash" meaning that each frame is repeated 3 times before moving onto the next. Instead of showing both the left and right image at the same time like IMAX, the projector shows the left image, then right image, left image, right image, left image, right image then the next frame. The system uses circular polarization allowing a viewer to tilt their head without losing the 3D effect.

lieMAX (digital IMAX) works using 2 Christie projectors. It shows both images on screen at the same time like a normal IMAX system. I have never seen a movie in this format and never will so I do not know if it uses linear or circular polarization or if it is double or triple flash. I would venture to guess it is triple flash since the Christie projectors are commonly used for RealD systems and so are made with this in mind.

Digital IMAX 3D uses linear polarization and is displayed at 24 frames per second (no double or triple flash). Being very flicker sensitive myself, it is so far the easiest of all 3D systems on my eyes.

Those JVC CR numbers - are they derived by the ANSI 16 block checkerboard method?

No, it's not an ANSI contrast number. It's full on/off. The JVC ANSI contrast is still pretty low, somewhere in the neighborhood of 350:1 or thereabouts. My Sharp 20K has an ANSI about twice that, close to 800:1. If the HDI contrast is ANSI 1,500:1, that's a phenomenal number. It just doesn't say. European contrast numbers, I believe, usually refer to ANSI contrast, but you won't find ANSI contrast being touted much in this country. For marketing purposes, it sounds anemic compared to the outrageous claims often used for dynamic contrast. That's why I wrote the email. As I said, they didn't respond.

LOL - CEM's are funny about E-mails.

Wrote Panasonic (on a Sat. on less) asking about their new BDT350 3D BD player and how the 2 HDMI outputs work. Got a response 2 HOURS later!

Wrote IMAX about how their Digital IMAX works - 2 days later - got a response.

Wrote Panasonic asking them how are they going to deal with 24P content with their 3D PDP if it's 120Hz total, 60Hz per eye - how are they avoiding the 2:3 pulldown. That was over 2 weeks ago - no response.

Panasonic plasma 3D HDTVs avoid using 3:2 Pull down by displaying the 24fps content they receive at 120fps. The fact that they only display 1/2 of the 120fps frames at a tiime does not mean that every frame of the 24fps incomig content that is displayed is not displayed the same number of times therefore avoiding rate Judder.

Taken sequentially the content is 48 frames per second. How do they display that at 120Hz refresh without judder?

This discussion looks . . . familiar.

Nearly every discussion should look familiar to you Lee. You are one of, if not, the most active member in seeking out knowledge in this field. We all are so glad of your participation on keeping us informed and setting us straight when we have been misinformed. You never get bored or upset with the same repeated quesstions and that is truly remarkable.

This thread is in my crosshairs as I have an old Sony HS-20 that I'm going to eventually repace with a 3D projector(s) and possibly a new screen as well.

Thank you very much. I do appreciate the kudos. And I am DEFINITELY not always correct in my "setting others straight."

I do appreciate the patience most people have shown me when I am incorrect.

Patience? If I wanted Patients . . . I would have been a Doctor!

I am a parent - patience required.

And it was I, who originally suggested how Panasonic was going to go from 24P to 60P without 2;3 pulldown.



Stay tuned and visit often!

Talk about deja vu.

It's dual light engine. meaning it's got two separate LCOS chips... well actually 6 separate chips since you have three for each eye (red, green, blue).

Think of it as two separate 2D machines in one... both projecting their independent image onto the same screen at the same time.

Only single-panel or single-chip sets would need double-resolution chips to do simultaneous left/right. If you have a dual light engine system, you solve the problem by simply having two 1920 x 1080p sources in the same box.

That's a description of IMAX theaters that use *active shutter glasses*. Not the ones that use polarized 3D.

Joe,

I agree that the weak contrast of this machine may be an issue. However, the first-hand reports were favorable, so there's a chance that laser light, which is more polarized that bulb light, but actually be perceived more dynamic than it measures. In any case, it's good to be cautious, but let's wait and see what comes. Given what JVC has done with native contrast, it's only a matter of time before the same improvements come to laser light sources on LCOS.