Film-Tech Forum ARCHIVE: Has anybody seen Dolby Digital 3D in action?

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Posted by Lyle Romer (Member # 1266) on 11-20-2007, 04:19 PM:

If you have, how does it compare to Real-D in all aspects (brightness, resolution, 3D effect, color reproduction).

The best thing I can see about Dolby's system vs Real-D is that once you pay for it, there are no ongoing licensing expenses.

Posted by Mark Gulbrandsen (Member # 72) on 11-20-2007, 04:28 PM:

Dolby 3-D blows Real-D(umb) right out of the water. Brighter, better color and you can sit anyplace in the auditorium including walking right up to the screen if you like and the 3-D effect stays the same...

Real-D(umb) is nothing more than another example of the half-baked cauldron of bodgery which is called 3-D at the moment!

Posted by Lyle Romer (Member # 1266) on 11-20-2007, 04:49 PM:

Does Dolby run at the same frame rate (144 fps, showing each eye frame 3 times) as Real-d or is it lower so the entire imaging chip can be used. If it is lower does anybody notice a difference?

Posted by Steve Guttag (Member # 268) on 11-20-2007, 11:13 PM:

One big zingger for the Dolby system is the current cost of the glasses. The cost of equipping a typical screen for just the glasses will often exceed the cost of coverting the projector and those glasses are going to have a limited lifespan. I know that Dolby is working on getting the costs way down but right now they are very costly...though kinda cool to look at.

You do need a fair amount of light with Dolby's system (seemingly as much as with Real D)...though you don't need a silver screen (the silver screen helps offset the light loss in the polarizer in addition to it keeping the polarization). Dolby uses a white screen, so you aren't going to get any real gain there...though with a pearl screen you might see a range from 1.5 - 1.8. The glasses are going to knock the light levels way down. Dolby was limiting the screen size to 40' on their initial roll out to ensure that it would look good.

Steve

Posted by Joe Redifer (Member # 3) on 11-20-2007, 11:27 PM:

Does Dolby use shutter LCDs?

Posted by Bobby Henderson (Member # 840) on 11-21-2007, 08:44 AM:

No. Dolby 3D does not use shutter glasses.

Regardless of that, the glasses currently in use are expensive ($50 a piece) and must be collected after every show and hopefully cleaned -if they can even be safely cleaned in an industrial/restaurant quality dish washing system most health departments would require. Count on a good number of customers damaging glasses. That situation is not exactly the most practical thing for a standard multiplex theater to accommodate.

Another problem with Dolby3D is that it only works with the Dolby Digital Cinema system. It isn't compatible with anything else. Real D works with any of the leading d-cinema systems, including Dolby Digital Cinema. For example, Harkins Bricktown 16 theater has one Dolby Digital Cinema equipped screen also equipped with Real D.

quote: Mark Gulbrandsen
Brighter, better color and you can sit anyplace in the auditorium including walking right up to the screen if you like and the 3-D effect stays the same...

The "brighter, better color" claim is questionable since the system Dolby is licensing from Infinitec obscures even more light than Real D and is limited to even smaller screens than Real D. Both Real D and Dolby claim they are working on ways to get their respective systems to work on large screens. For the time being, the only way to get 3D to work on giant sized screens is with IMAX-3D.

The "3D anywhere in the auditorium" comment actually makes me wonder how "fake" (using Joe's description) Dolby 3D looks anywhere in the auditorium.

Both Real D and IMAX-3D work from two discrete left eye/right eye images. And, yes, if you sit right up in the front rows objects that are meant to poke in viewers' faces (such as the knitting needle in the Coraline 3D trailer) will seem to split in two for those viewers too close to the screen.

I've watched Beowulf twice in Real D and both its color quality and 3D quality were very good. On the 2nd viewing, I walked around in various places in the auditorium and the 3D held up fine. Again, only in the very front rows things could get a little wacky (objects doubling when poking at the audiences' faces and a little bit of ghosting).

The licensing cost issues with Real D are the only thing I think can get that system in trouble. However, I doubt companies like Carmike Cinemas are really paying $20,000 per year per screen to rent the Real D equipment. They wouldn't stick 3 of those systems in a modest 8-plex in little 'ol Lawton, OK if the cost was truly that high. I'll bet some kind of volume deal was worked out between Carmike, the movie distributors and Real D.

And finally from the customers' point of view, they're paying a $2 premium (or more) to see Beowulf in 3D regardless of whether the movie is in Real D or Dolby 3D. No difference there.

Posted by Joe Redifer (Member # 3) on 11-21-2007, 09:07 AM:

quote: Bobby Henderson
No. Dolby 3D does not use shutter glasses.

Then why are they $50 each?

Posted by Mike Blakesley (Member # 26) on 11-21-2007, 10:19 AM:

I would guess it breaks down something like this:

$5.00 for the technology
$20.00 for advertising
$25.00 for the Dolby name

Posted by Bobby Henderson (Member # 840) on 11-21-2007, 10:49 AM:

I don't know why the glasses cost $50 each. The price quote on those glasses is according to a c|net news article about Dolby 3D: (linky linky). I can only guess the lenses in the glasses have to do some color filtering trick with that spinning color wheel mounted to the projector and that filtering technique is difficult to mass produce in lenses.

Shutter-based glasses work well, but are expensive to produce, require infrared synchronization with the projectors. The resulting 3D effect is good, but subject to flicker since techniques like triple pass cannot be used. Most IMAX 3D screens I have visited only use standard polarized glasses. Very few go to the expense of using the LCD shutter glasses and PSE speakers in the headset.

Posted by Peter Castle (Member # 1997) on 11-21-2007, 03:48 PM:

The method used by Dolby 3-D involves using narrow pass filters so that the red/green/blue base colours used to produce the full colour picture have different frequencies for each eye - but not that different that a colour shift is detectable. The production of the narrow-pass filters are, it seems at present, expensive.

I've only seen a few examples of Dolby 3-D and only in a small demonstration room, but the effect is as good as Real-D without any noticeable colour change.

Posted by Brian Michael Weidemann (Member # 2243) on 11-21-2007, 06:44 PM:

The eyes can adapt quite well to color balance differences between them. Wear the classic red/blue glasses for ten seconds while staring at a white wall, take the glasses off and look at that same wall with each eye on its own.

If one eye sees basically the same image but with a slight frequency shift, the brain will very quickly interpret both eyes as seeing the same colors.

Considering how long my own eyes take to recalibrate themselves after even 10-20 seconds of red/blue glasses, I'm wondering if 90-minute exposure could affect my eyes more permanently, even if by such a narrow band.

Posted by Joe Redifer (Member # 3) on 11-21-2007, 07:30 PM:

What I do after wearing red/blue glasses for a few minutes is swap them so that they are backwards for about 5 to 10 seconds. That helps my eyes recalibrate faster.

Posted by Hillary Charles (Member # 769) on 11-22-2007, 08:47 PM:

Is there any word about these "flicker" types of 3D triggering epileptic seizures? Or are they completely safe for epileptics?

Posted by Bill Enos (Member # 440) on 11-22-2007, 09:09 PM:

Are the Real D glasses the same as the ones used for the past 50 years for film 3D ?

Posted by Scott Norwood (Member # 30) on 11-22-2007, 10:13 PM:

Real-D uses circular polarizers, which reduce the effect of tilting one's head while viewing polarized 3D images. The glasses also use circular polarizers and aren't interchangeable with regular Polaroid glasses. Not sure on the cost of the Real-D glasses, but I assume that they are more expensive. The Chicken Little glasses were (are?) made of plastic...not sure if their regular glasses are plastic or cardboard.

Posted by Bobby Henderson (Member # 840) on 11-23-2007, 12:11 AM:

Real D glasses look like Ray Ban Wayfarer glasses. The frames are black plastic with decent build quality. The lenses are thin plastic that can bend a little when pushed with a finger. These glasses are a step up from the cardboard glasses I got when seeing 3D movies in the 1980s.

I think Real D should put out a batch of red colored glasses when U23D is released.

Posted by Ray Faultless (Member # 903) on 11-23-2007, 04:48 AM:

Over here the glasses are not collected after the show.We pay an extra £2 to see Beowulf which I thought was for the glasses.They come in a sealed plastic bag.

Posted by Chris Slycord (Member # 4239) on 11-23-2007, 07:25 AM:

That's likely because you saw it in RealD and not Dolby's 3D.

Posted by Mark Gulbrandsen (Member # 72) on 11-23-2007, 08:30 AM:

quote: Hillary Charles
Is there any word about these "flicker" types of 3D triggering epileptic seizures? Or are they completely safe for epileptics?

That reminds me of my neighbor back in the Midwest whose 60 hz flickering computer monitor caused her to have epileptic seizures. Her doctor couldn't figure it out and I finally one morning hit the nail on the head as she had called us and was sitting in front of her computer when she had a seizure, I heard the phone hit the floor and I called 911... raising the monitor scan rate to 72 hz brought an end to the computer induced seizures! I will call and see if she has been to see any of these 3-D films....

Mark

Posted by Hillary Charles (Member # 769) on 11-23-2007, 09:46 PM:

Mark, that story is exactly why I am concerned. You never really know what will trigger those seizures.

Yesterday, one of my relatives told me that she and her daughter saw "Beowulf" in 2D and would like to see it in 3D. Since it doesn't appear the local IMAX is planning to run it, we're hoping to see it in digital 3D. She is epileptic (and her daughter has shown signs of it), and my fear is that the alternating left/right flicker could trigger a seizure. I'd like to take them to the 3D version, but would feel awful if anything like this would happen.

Posted by Tim Reed (Member # 137) on 11-23-2007, 10:19 PM:

I will get some kind of trip-out seizure at certain rough textures or patterns, if I'm not careful. I have to look away and put it out of my mind, or do an exceptional job of ignoring it.

When I worked at Hadden, I had to be especially careful not to stare at the stacks of rough, cardboardy, peaky, triangular corner-protectors that came with the Middle Atlantic racks. [Eek!]

Like THIS! (I can't look at this for long, particularly should it be flipped top to bottom, or I'm a goner..) Sounds crazy, I know. But at least I know what to AVOID!

Posted by Joe Redifer (Member # 3) on 11-24-2007, 12:40 AM:

quote: Tim Reed
I can't look at this for long, particularly should it be flipped top to bottom

Do you mean if that picture you posted were upside down, you'd trip out?

Posted by Mark Gulbrandsen (Member # 72) on 11-24-2007, 09:31 AM:

quote: Hillary Charles
Mark, that story is exactly why I am concerned. You never really know what will trigger those seizures.

Yesterday, one of my relatives told me that she and her daughter saw "Beowulf" in 2D and would like to see it in 3D. Since it doesn't appear the local IMAX is planning to run it, we're hoping to see it in digital 3D. She is epileptic (and her daughter has shown signs of it), and my fear is that the alternating left/right flicker could trigger a seizure. I'd like to take them to the 3D version, but would feel awful if anything like this would happen.

I would make a call to Dolby on that one for sure... 415-558-0200 and find out the exact flicker frequency and I would think that as long as its out of the normal perception of human sight that it would be ok. They might also be interested in any feedback from your friend after you all see the film.

From my experience with my next door neighbor I would say that the flicker definately needs to be higher than 60 hz. I will try to contact a local friend today that is in charge of the two Dolby 3-D systems here in SLC and see if he can also give me any pertinant data for you. An attack would definately be awful to say the least because depending on how bad the seizure is it can also mean hospitalization and so on.

Mark

Posted by Bill Enos (Member # 440) on 11-24-2007, 12:19 PM:

Anybody know what process is used by Busch Gardens in their 3D rides. I've been on the Dark Castle ride at Busch Gardens Williamsburg and found the 3D effects to be very good though for the most part there was little color.

Posted by Hillary Charles (Member # 769) on 11-24-2007, 01:14 PM:

Mark, Thanks for the number and whatever info you can find. I know the mother is on medication to control her epilepsy, but that's never 100%. Even driving through trees that intermittantly block the sun can trigger a seizure, if the speed of the car is just right. And once that happens, her driver's license can be suspended for two years, a rule that is not convenient, but is totally reasonable.

And Tim, I've never heard of your condition before, but the idea of certain patterns causing problems makes sense. The rough textures aspect seems very unusual. Is it?

Posted by Tim Reed (Member # 137) on 11-26-2007, 09:08 AM:

Hillary, yes, I suppose so. It's more the patterns that the ridges of a rough texture form (out of negative space, maybe - I'm can't look at them long enough to determine without "stepping off the precipice"). It's just something that happens with me. It's bizzare, I know. I always figured it might be associated with epilepsy. Thankfully, I haven't had "an episode" in probably 15 years.

When I was 16 or 17, I was having seizures regularly for several months (once, while driving!). The doctors ran all kinds of tests on me: EKG, brain scan, etc... but never pinpointed what was causing them. Since then, I've felt them "coming on" at these certain patterns. It's very scary.

quote: Joe Redifer
Do you mean if that picture you posted were upside down, you'd trip out?

Judging from the feeling I get by that photo (which I found randomly on Google images), yes, I'd be more prone to be "affected" by it, if it were inverted. It very much resembles the Middle Atlantic rack corner protectors that I had to avoid.

Posted by Mark J. Marshall (Member # 1409) on 11-26-2007, 10:26 AM:

Wow, Tim. That has to be a strange feeling.

Posted by Dave Macaulay (Member # 813) on 11-27-2007, 10:13 AM:

There should be about the same amount - or less - flicker from a digital 3D system as with a film projector.
I understand Digital 2D systems don't flicker like film projectors as they don't need the long "dark" time the intermittent takes to move a film frame, they blank for a very short time when refreshing the frame image and each pixel has a different ON time depending on its brightness... I'm probably wrong in some way but that's my interpretation of what I've read about the TI system. 3D would presumably have to blank for a while when the filter wheel is between sides, so it might have more flicker than 2D.
The seizure inducing effect from flashing lights (especially strobes) is strongest at about 3 Hz and very weak (basically zero) at the 48 Hz flicker rate of standard film projection.
We built a strobe in high school and one kid was really interested in it, he held it in his face and stared directly into the reflector for about 10 seconds before falling down and having a massive seizure. We (his classmates) didn't know he had epilepsy before that. It was flashing at just about exactly 3 Hz as the circuit was weak and above that rate it would get progressively dimmer.

Posted by Bobby Henderson (Member # 840) on 11-27-2007, 10:25 AM:

There should be no noticeable flicker at all with "digital" 3D. Real D triple flashes each left eye and right eye frame alternately. Unless your eyesight can somehow see well above 72 frames per second (and you have a lack of persistence of vision) you should not see any flicker.