CurtPalme.com Home Theater Forum

[Tom.W]

How many lumen ?

[achase]

34,000

[Tom.W]

That should do it ...

[achase]

Not really for Dolby 3D!

[jask]

excellent.... you can also use it to kill vampires and correct macular degeneration when you are not playing Call of Duty or watching movies.

[AnalogRocks]

I wanna play Space Invaders on it!

[AnalogRocks]

I wanna play Space Invaders on it!

[achase]

[Tom.W]

[achase]

I not saying that exactly. There are many (commercial) 3D systems out there, each one with it's pluses and minuses. The controlling factor here is really the screen, with the screen material as the item in particular.

Since my screen is a Stewart Microperf, with a matte material (Gain=1), it is not suitable for any 3D system that relies on polarization to achieve 3D. Thus the "RealD" and "Master Image" systems will not work for me as they need a "silver" material screen to maintain discrete left-eye/right-eye circular polarity. The main problem with a silver screen is that it does not provide a uniform lumen level across it's surface, resulting in hot-spots and dim areas. Likewise, the IMAX 3D system (even if it were available) uses linear polarization.

That leaves two choices: The XPAND system or Dolby 3D. Since the XPAND system uses active shutter glasses, one has to deal with a heavier set of glasses, flash inducing headaches, recharging and synchronization issues, as well as licensing issues and ongoing payments as I am dealing with more than 100 seats. That pretty much leaves the Dolby 3D system as the de-facto choice since it works just fine with a non-silver screen (it uses a spectral differentiation technique).

In my experience, the Dolby 3D system provides the absolutely best 3D, with both colorimetry and image sharpness superior to the others. The glasses are available with real glass lenses, and there are no ongoing fees. As you know, there is no such thing as a "free lunch", and the downside of the Dolby system is it's low efficiency.

ALL of the 3D systems have incredibly high parasitic losses. They range from a "best" case RealD 3D XL efficiency of 28% to a "worst case" Dolby 3D of 10% (!). The polarization systems that use a high-gain silver screen can make up some of the loss, but in my case the only arrows in my quiver are lumens.

The theatrical "standard" for cinema projection is 14 foot-lamberts. Most theaters can do this with 2D, although many choose to run their lamps at lower levels to gain additional lamp life, since these things are VERY expensive to replace. 3D is a whole other beast. Many theaters typically manage only 3 - 4 FL or so, with 6 Fl the target now (assuming a theater can do that).

My goal was to operate at about 25 Fl for 2D (not a problem for me), and 14 Fl for 3D, but the best I'm going to be able to do for 3D will be about 8 Fl.

To do what I want to do for 3D light levels would require a 12KW lamp, and that's not possible to do with this projector, so until the laser projectors arrive, 8 Fl it is.

[ecrabb]

[achase]

[ecrabb]

[stefuel]

[achase]

[Tom.W]

So Arnold how is that new Digital working out ?

[Spanky Ham]

Shocking that Tom hasn't updated this in almost two years.

Arnold can probably go a little longer with this light valve, but Barco has a new laser DLP that puts out up to 56k lumens. It costs half a mill and has sh$tty on/off cr, but the picture does look good.

[Shane32]

[donaldk]