Film-Tech Forum ARCHIVE: Dolby 3D or XpanD

my profile | my password | search | faq & rules | forum home

»	Film-Tech Forum ARCHIVE » Operations » Digital Cinema Forum » Dolby 3D or XpanD (Page 3)

This topic comprises 3 pages: 1 2 3

Author

Topic: Dolby 3D or XpanD

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 06-19-2011 08:39 AM

Why wouldn't you use Dolby on a "new" large screen? Silver screens suck on many levels (color, light distribution...etc). Using 2-projectors solves much of the light issues with Dolby on such screens. Furthermore, it naturally cuts the light way down on 2D so both 2D and 3D are in a better range.

-Steve

| IP: Logged

Carsten Kurz
Film God

Posts: 4340
From: Cologne, NRW, Germany
Registered: Aug 2009

posted 06-19-2011 03:02 PM

Because the light drop is just too much for a large screen, even with the largest bulbs. And a dual projector Dolby 3D setup is extremely expensive, also to maintain.

I don't like silver screens, but for large screens there is not much choice in my opinion. I guess I would even choose Volfoni/shutter glasses over Dolby then

Let's see how Panavision or the new Infitec performs.

- Carsten

| IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 06-19-2011 06:35 PM

I would go with a dual projector Dolby 3D, easily. It will be the best looking picture. Going with two projector gets you up to more than 20% efficient...only beaten by Real-D XL but without the drawbacks of Real-D and the XL box.

-Steve

| IP: Logged

Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 06-19-2011 08:04 PM

Steve.... I have to laugh... One side of you pushes two projector Dolby 3-D while the other side of you talks about the drawbacks of the XL (misalignment because there are no other drawbacks..). Now get it straight please! Any two projector 3-D system is going to have misalignment that would exceed the XL specs by a ten to one margin and even greater the shorter in focal length you go! How many of both have you installed? Most of the XL's that I have done have aligned perfecfly at center and to within half of the three pixel Real-D spec at the sides and several were perfect! A couple have been at the three pixel spec. And once adjusted it stays put. Even as close as you can get stacked Barcos or brand C or brand N you'll see in excess of 10 or more pixels of reg error on all 4 of the the sides when the center is dead on. Frankly there is no comparison. Also, Dolby still requires a gain screen... you and I of course would use a maximum of 1.4 however... Dolby reccomends a 1.8 gain MINIMUM and one can assume that Harkness has sold a ton of the 2.2 gain surface for Dolby. That 2.2 gain Harkness surface of which I had one and only one experience (Thankfully) is actually worse than a silver 2.0 gain as per the hot spot. I think in the every day theater with either Dolby or Real-D you are not going to see a whole lot of difference in light distribution.... At the end of the day though that XL based projector is going to have much much lower lamp and electricity cost... In many cases one could buy and use the mid sized projector over needing the larger one that takes the 6 or 7 kw lamp you'd need for Dolby. Oh and the twice as expensive lens. I love Dolby's 3-D effect and the color is very acceptable but from a cost to operate standpoint I'd bet that Real-D XL and Dolby 3-D on a 45 foot wide screen would be exactly the same. As far as owning it... makes little difference really. I don't believe either will become door stops in the booth as 3-D is here to stay but we will certainly see less product down the road and that Dolby will have a much longer payback time as a result.

| IP: Logged

Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 06-19-2011 10:29 PM

quote:
Steve.... I have to laugh... One side of you pushes two projector Dolby 3-D while the other side of you talks about the drawbacks of the XL (misalignment because there are no other drawbacks..). Now get it straight please!

Laugh at your ignorance! In an XL system, you are projecting THE SAME IMAGE and trying to overlap...any mis-alignment comes off of resolution. In a dual projector system, you are projecting two DIFFERENT images. Any misalignment comes off of 3D accuracy. You are trying to compare apples to wrenches...there is nothing to compare...try again.

quote: Mark Gulbrandsen
Also, Dolby still requires a gain screen... you and I of course would use a maximum of 1.4 however... Dolby reccomends a 1.8 gain MINIMUM and one can assume that Harkness has sold a ton of the 2.2 gain surface for Dolby.

Blah, blah, blah....again BS. I have multiple installations with Dolbys on MATTE WHITE SCREENS! I have them on curved gain screens. It is all about the size of the screen, light available and design of the system as to what you "need."

I could definitely see how a 2.2 Harkness "Pearlux" would look as bad as a Silver, in terms of hot-spot as a 2.2 Silver...though color rendition would almost have to be worse on the silver. Then again, if curve the 2.2 Pearlux to an R=2/3 - 5/6 Throw it would probably yield a reasonable distribution in the horizontal plane. It would still be gainy vertical (one would see a bright band of light in the center from side-to-side and then falling off as one goes to the top/bottom. As always, the lower the gain, the better.

quote: Mark Gulbrandsen
At the end of the day though that XL based projector is going to have much much lower lamp and electricity cost...

Yes, that is true...but a much higher per-show cost. At $.50/ticket...how many ticket sales does one have to have before they far out paid the cost of the lamp/electricity of Dolby? It isn't a close call, Real-D is THE MOST EXPENSIVE SYSTEM out there. Do the math. If a theatre AVERAGES just 100 tickets a day (not even a show) over the course of a year (some days not so good but during the summer, much more...so an average 100/day). At 50-cents a pop, that comes to $18,250.00 to Real-D. Thus, in less than a year's time, Real-D is already more expensive than a single projector Dolby 3D system...even with the more expensive lamps. Real-D typically has a 10-year contract. That comes to $182,500.00...I believe I've heard there are 5-year deals...it is still $91,250 on just a measly 100 tickets/day average. In less than 2-years time, Master Image is less expensive that Real-D...even at their absurdly high price for the mechanism.

Personally, I do think 3D is heading away and regardless of if they become doorstops...Real-D will be more expensive than either Dolby or Master Image to the exhibitor if 3D lasts even one or two more years (which I think it might).

quote: Mark Gulbrandsen
If you're looking to buy then go Dolby if you're looking to play then pay then go with Real-D XL. Other than stacked projectors the XL still produces the best contrast range of the filtered 3-D systems and it rivals the contrast range of 2-D. Dolby can't do as much contrast range because of inherent limitations of the color bandpass system.

Oh...and what is with this pseudo-science? Contrast "range" do you mean "ratio." Either way, in a theatre, the limiting factor is going to be the maximum white the system can put out versus the darkness the theatre can achieve while still meeting fire codes. Since the spec for 3D remains at 4.5 +/- 1, the Top of range is set. Now, the lower the gain of your screen (until 1.0) the better your contrast ratio is going to be over the entire surface...Real-D is hosed there...they are always going to be down at about 1.5fL in the corners. Since Real-D starts ghosting first, they have an inherent limit on how bright they can go.

Not to worry...when the wind blows a different direction, I'm sure you'll have a different recommendation for all.

| IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1 2 3

Printer-friendly view of this topic

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.