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Discussion in 'Blu-ray and UHD' started by Paul Hillenbrand, Aug 19, 2008.
Wonder if the 3D is in the old-fashioned "anaglyph" red/blue process or full-color 3-D? Paul
Whenever the glasses are included it's anaglyph. They would never have 4 field-sequential glasses in each dvd box.
I've never known 3D on video to work well using the red-blue glasses.
Not only is it headache-inducing with colors being skewed, but it's impossible to get perfect cancellation due to the color controls on your TV not perfectly matching the filters. The few times I've seen anaglyphic 3D, I never experienced a good "lock" on the 3D effect.
What's frustrating is that the BD format has the bandwith to store two alternate-eye 1080p24 video streams for REAL 3-D... but the BD group won't act to get the spec into the format. IMO, it would be an awesome optional spec... like profile 2.5 or something. -dave
Actually, TDVision has been proposing such a format for Blu, and is trying to push Sony to include it in one of their PS3 updates. ...We shall see...
I don't suspect we'll see Real D in home systems until consumer home entertainment manufacturers figure out how to produce a 144 Hz display without breaking the bank. In addition, for direct-view displays (LCD, plasma), they'll have to develop 144Hz LCD shutter glasses. Anything less would be a lesser approximation and unsatisfactory.
I saw a demo of 3-D on a Mitsubishi 73 inch rear projection 120 HZ tv and it looked fantastic. No color problems that you have with anaglyph and no flicker like the current 60hz field-sequential systems. You would need a Blu-Ray player to be able to put out a 120 HZ and a system to do the field-sequential signal in 120 HZ.
Once you get the feature in the spec it's up to the hardware manufacturers to decide how to deliver it. A 3-D Blu-ray player could matrix the two alternate eyes into a 1080p48 progressive signal (no "fields" here... just full frames) or 1080p60 or 1080p120 etc... and then the TV could sync with shudder glasses. OR you could output dual HDMI to two separate projectors using poloraized light filters projecting onto the same screen... like at IMAX. Considering that you can get a 1080p projector for $2k these days, that's not an impossible scenario. And any serious 3-D buff would KILL to be able to watch "real" 3-D on the big-screen like this. Of course, you could use LCD glasses with front projection too. No reason why a projector can't run at 120 Hz either.
But why compromise with 120 Hz? Real D is designed to run in one projector with alternating frames running through clockwise and counterclockwise polarised filters. Each frame for each eye is displayed 3 times (72 Hz), which doubled is 144 Hz, in order to reduce filcker to near imperceptible levels. When this technology is affordable for home use is when 3-D will be a reality on the home set.While I'm aware that there are competing systems, they all run on pretty much the same principles, and as I said before, I'd rather wait and see Real D @ home than settle for a lesser approximation. Frankly, I was blown away by Real D, even moreso than IMAX 3-D.
I wouldn't call 120hz a true compromise when it's compared to 144hz. Check it out yourself first, as it's double what field-sequential 3-D can do at NTSC's standard 60hz rate. In the late 1990's I ran frame sequential 3-D on my computer, and could vary the refresh rate. At 85hz, the flicker was basicly gone, and at 100hz, a totally white screen showed no perceivable flicker. 120hz (unlike 144hz) also works nicely for both 24fps film sources and for 60hz sources. The Consumer Electronics Association as well as SMPTE have recently set up task force groups aimed at determining optimal 3-D standards for 3-D video, as there are currently a number of ways to encode 3-D video, with anaglyph providing the lowest quality. Anaglyphic (red/blue) 3-D video keeps returning simply because if you provide some cheap-o 3-D glasses, it's then "3-D ready" right out of the box, even with it's limitations. But if a unified stereoscopic encoding standard can be agreed upon, it will help things along greatly.
How the hardware outputs the signal is up to the hardware and display. You can do anything you want with the signal. 144Hz... go for it. What matters is getting the stereoscopic video signal ON THE DISC in native L/R 1080p24 (2 channel). Then, the palyer can matrix that into 1080p48, 1080p144, or dual HDMI each running a single 1080p24 channel for dual-projection. GET IT ON THE DISC. That's all that matters now, and Blu-ray has the bandwidth for it. Then, as displays evolve, the hardware can output it to match.
Not a bad idea, so long as the special features maniacs don't kick up a stink in the following manner: "Why the hell do I need a separate 3-D stream if I'm never gonna watch 3-D?" Don't say it won't happen, because it WILL.
Let's dream a little! Brainstorm party anyone? Full-color IMAX 3-D picture quality with one-projector having a dual polarized lense system, taking advantage of one bulb for equal light output. This would take advantage of current space availability, give it an efficient energy consumption value while adding a factory calibrated synchronization system, making it easy for dual frame alignment, a must for those not technically inclined. Paul
That's what Real D is: one projector, displaying alternating eye frames through clockwise and counterclockwise polarised filters at high speed to reduce flicker.
BD allows for full 1080p of the secondary video channel. That's all you need, other than a spec for how players should output that stream (second HDMI and/or matrixed into the same HDMI signal as the primary for alternating-eye). That's just firmware updates. Get a player with the processing power for full 1080p resolution with the secondary (PIP) video stream. That's 100% compatible with all 2-D systems, as if you don't choose to watch the secondary video stream, you just get the primary stream without any problem. In other words, any 3-D BD using secondar video stream approach would be 100% backawards compatible with all 2-D players.
Nearly 20 years ago now, the Japanese first began working with 3D systems using the then-new Hi-Vision video equipment. Quite a variety of different systems were developed, including field-sequential (remarkably acceptable, since each field had more resolution than an NTSC frame) and parallel. From what I can tell, one of the more commonly-adopted approaches, to the extent that it was actually installed in venues across Japan and the USA (for entertainment & other purposes) was to have each eye's program on a separate videodisc (typically the uncompressed format, not the consumer MUSE disc with its longer playing time) & feed two projectors from two interlocked & synchronized videodisc projectors — remembering that the timecode embedded in the videodisc allows for lining up the frames properly in time. Obviously, this isn't a consumer-friendly solution, but it's high time that a standard method for handling 3D high definition content is agreed upon. The old VHD (Japanese vinyl videodisc, not to be confused with RCA's CED) had the capability, back in the early 1980s, to output field-sequential 3D and triggering pulses for shutter-type glasses, and due to unique features of the standard, the same discs could be played back in ordinary 2D ; running time of the 3D-encoded discs was half that of standard movie discs. If Blu-Ray can store two simultaneous image streams, there's no obvious objection in my mind to simply putting two HDMI ports on the back of the player & specifying the capability to put both streams out at once. Then the disc standard wouldn't be tied down to any particular implementation, and the two-projector method could be done practically out of the box, although if you wanted field- or frame-sequential you would need some kind of outboard processor to generate the alternating sequence & trigger pulses.
But this method requires the use of projectors, leaving the vast majority of consumers out in the cold. Doug
But Doug, any player manufacturer could then offer a firmware update to allow the user to optionally matrix the two signals together ala "alternating frames" for LCD glasses with any display of any type. Dual HDMI output just leaves every option on the table (you can't add a second HDMI output with a firmware update, you need that hardware solution on the physical machine). No one is left out. Doug, that frame-sequential (better phrase than "field" sequential when we're talking about 1080p) will work on ANY display of any kind. Not just projectors. You just need the synchronized LCD glasses.