CurtPalme.com Home Theater Forum

[stridsvognen]

If your curious, the line mod is a fast one to do, you can test it yourself, i think i have tested it with 3-4 different resistor values, and a trimpot solution, on different VIM boards, and i just prefer its not there at all.

Trying it yourself is the only way you will know.

How do you calibrate your setup.? What is your gamma adjusted to.?

[tschaeikaei]

Hello, we moved to another apartment, and now i'd like to hang my two 8500 to the ceiling.
I searched this site and the rest of the internet, but couldn't find hardly anything about stacking
and /or 3d.
The projectors should run on a PC with a graphics card with two DVI slots, the pictures should be separated
by software.
The 3d hardware should be color filters (Dolby 3d) or (if dolby is too expensive) like "real d", circumpolar polarisation.
Anyone done that? Who can give me some links about stacking?
If you have something in german, please i am german, english is possible for be, but exhausting when it's much to read.

Thanks a lot, Julian

stridsvognen: gamma settings on the pc were at standard, but this will all change, the projectors aren't mounted yet and when they are, they will run on another pC and graphics card.
So i will have to do a complete new setup on both.

[draganm]

stacking or Blending?

Stacking. The marquee's were designed to be stacked but only in an over/under configuration. I don't think you will be able to stack 2 x 8500's side by side. There's not enough geometry controls with normal Marquee's. If they're both Ultra's, then maybe but you will have to run a pretty big screen to decrease the toe-in (V-angle of machines)

Blending: it sounds like your looking to do edge-Blending with a PC but AFAIK none of the PC based solutions is worth a sh*t. Cheapest option is the TV- one units. Do a search for tV one

http://www.tvone.com/edgeblending.shtml

[tschaeikaei]

Yes stacking seems to be the right way. But: My room is 2,6m (8.3ft) high.
One projector is 43cm high, so if I place one on top of each other, I will loose 1m (3.3ft) room height.
Thats really bad.
Blendung means taking both projectors apart and mounting all six tubes and lenses in one case together?
Side by side would be far easier to do.
I dont want to do edge blending with a PC, I want to project both pictures on the same part of the screen.
The pictures i meant are the 3d-half pictures of a film. They should be projected one on (not on top of) the other.

I dont like the idea of stacking over/under, because of the mechanical and electronical setup,
when i need to lift the projectors covers.
But a side by side stack seems only possible by using a small picture width and height, off-center the tubes.
I thought it would fit by bringing the two (side by side stacked) projectors out of parallel, e.g. turning the right proj. a bit to the left and
the left to the right and adjusting scheimflug far more than commonly used.
I would have to build a scheimflug correction for the green tubes too, and maybe change something on the others.
But... is that possible?
The tube width should be used as far as possible.

[Nashou66]

Your ultras will do side by side no problem.

They will be touching each other. if you remove the case and then make a hush box you can get them even closer.

For passive 3D you will need to put polarizing lenses in front of the three lenses. Barco made a system for CRT.

Also Fast phosphor green crt's work best. check to see if yours are .

[Tim in Phoenix]

Hello

Try this out on the floor first; you are looking at a minimum throw distance of 13-14 feet on a 9 or 10 foot screen width. Any smaller and the edges won't converge. You will need to display a grid from DVD, the onboard test patterns are no help for stacking.

[tschaeikaei]

Yeah, my hope has become real:)

Nash:i read about your longbows yesterday evening (funny story btw.)
but as i mentioned, english is kind of hard to read to me if it is much text..
the pictures in the thread are also gone. did you do a side by side 3d stack?
If so, did you use polarising or dolby filters?


14ft is much (4,3meters, right?), so i can't use all of the phosphor width.
This throw distance would be possible, and yes, both of my 8500 Ultras
have P43 phosphor on green.

They were mounted in a 3D application at some institute
as the reseller told me. They wanted to throw the projectors away, so he took them home.
but he didnt take the polarising foils. then the proj. appeared on ebay and thats why i got
2 8500 ultras and a pg9 all about 500 hours and 9 rated tubes together for 200€ (276 USD).
maybe i suck.

Tim:
the idea "first try on the floor" is a good one, i would definitely do that.
is it important wich lenses i use for 3d, could eg. hd 145 be possibly better for this "scheimflug-intense" application?
I have the uncolored HD8 Rev.B, for normal 2D viewing they were ok.
Would it be positive to move the two blue tubes to the outer side,
so (if i count the row of six tubes, blues will be no 1 and 6)?
The idea is that blue has not to be that sharp on the screen like green or red.


found these foils: http://www.polarization.com/polarshop/product_info.php?cPath=22&products_id=50
has anyone tried them?

It is not mentioned how much light will be lost through them, but for that price i would give them a try.

The problem not mentioned yet is that a silver screen is needed for polarised 3d.
Any ideas on that? do you use silver screens?
I would prefer a dolby system btw, it should get a better image by loosing much less light
than a polarising system, get better colors and a silver screen would not be nessecary.
Problem is the filters, i have no idea, where i could get those dolby color filters or how much they cost.
the only thing i know that there are different systems and the glasses are about 35USD each.
some info anyone?

[tschaeikaei]

Found the pics: http://www.curtpalme.com/forum/viewtopic.php?p=365588#365588
I'm wondering about that space between the projectors.
Or is this a 2D blend and each projector does only one side of the image?
do you run each on 960*1080 that they generate 1920*1080 together?
Tell me, Nash.

[Tim in Phoenix]

Hello

HD145s may call for a shorter throw, which is not helpful in a side stack.

[Nashou66]

[tschaeikaei]

One pair (they are sold as pairs) would fit for 6 HD 8RevB lenses.
They are 16cm in Diameter.

But: I would prefer the Dolby solution. More light and no silver screen needed.
Anyone tried that?

[tschaeikaei]

Someone in a german forum told be that it would be best to use a curved silver screen
for RealD (circumpolar) for 3D.
The problem with polarisation for me always was that i would have to use two screens, a normal white
for 2D and a silver one for 3D. But.. why not use the silver one for 2D?
If you don't get hotspotting on 3D, it should work with 2D, too.
Maybe it would be too bright, but is there a "too bright" in CRT projectors? If so, just lower the contrast and it's done.

So: would it cause any problems, bad colors or so if a curved silver screen is used for 2D?

One time again: Has anyone used the DOLBY 3D method on CRTs yet?
Best regards, Julian

[stridsvognen]

I dont belive its possible to optimice a projector setup for both 3D and 2D, you need to find out which you prefer, alone the P43 green will make 2D look bad.

If i had to make a 3D setup i would go for a 2X DLP solution, and use the CRT to what its good at, and try to make that as good as possible.

Im also sure it will be a cheper and better solution.

[tschaeikaei]

Hey stridsvognen,
I understand your doubts. It would by far be easier to use DLPs, the external equipment and tweaking time
would be neclectable small, BUT: i have the 8500 Ultras in the corner of my living room and they work both well.
Why buy two DLPs?
But lets say something about hobbies: if you don't try every way and every possible solution, it is no hobby.
We don't have to watch movies, we do it because we like it.
And so it is for me with CRTs. I'm in love with those complicated massive machines, but if it has to be 3D,
then produced by two CRT projectors.


the guy from the german forum told me, that his curved silver screen works fantastic with 2D on
a single G70. He hasn't set up the second G70 yet, but is planning to use the circumpolar RealD solution.
I'm planning to do this with the two marquees the same way.

Or, if it is affordable, the Dolby3D system. Any links on Dolby?


That was one of my biggest doubts: using a silver screen for 2D. But colour seems to be really good.
If the optical failures caused by a side by side stack (skew, tilt, sharpness and scheimflug issues)
are balancable (in the menue, by physically aligning the tubes and maybe an extended scheimflug)
i'm proud of myself.

Still looking for people, who did this, saw this, planning this.

Best regards, Julian

[Melifluonze]

Hey, Julian,

You do suck! Great price on the 8 500 ' s

I'm working on stacking for 3d too (passive) or just for more contrast. I'm putting one on the ceiling and one on the floor when I do. The hush box of the one on the floor will be an "end-table"!

-Melifluonze

[stridsvognen]

[tschaeikaei]

Yes, shure i will.
But, first i need to know more about Dolby 3D. Wich i would prefer (if its somehow to realise
and affordable).
DIY is written in capital letters .

Thanks so far, keep me informed if you know more than i do (wich i bet do most of the people here).
I will post every time i get more knowledge.

[tschaeikaei]

Today, i phoned infitec.
The guy told me that their filters are made of glas with a special coating
and for 6 filters that big to fit to two CRT projectors would be about 10.000€ (14000USD).
Thats a bit too much for me. I will call Dolby Munic at monday,
but it seems that i have to use polarisation filters.
Some people at a german cinema forum told me, that infitec systems do not provide better
light efficiency than realD systems do.
The channel separation should be a bit better with infitec/dolby, and colors seemed
better to me as i seen both systems in cinemas. But the difference is not that much.

I still think, dolby /infitec is better, but sircumpolar polarisation (realD) is good, to.

Best regards, Julian

[barclay66]

[tschaeikaei]

First one question, before i start my story about 3D systems:
I need to know how to color correct a projector, that has fast (P43) green.
Is there someone with experience in that?
Do you have links? I was wondering to find nothing on google, because those P43 greens
need filtering more than the "normal" greens. Their colour is way off and it is (to me)
impossible to get a greyscale thats anyhow acceptable.

The story about 3D from a viewer without measuring equipment in cinemas:

The idea i have to tell you is the simplest one there is (exept of shutter technique):
I'm going to do it with linear polarisation. But one after another:
I've seen all popular 3D systems now in cinemas.
Circular (Real-D), Interference (Dolby), linear polarisation (IMAX).
Visited the IMAX 3D theater Sinsheim today.

My thoughts (and those of my girlfriend, who is kind of neutral because
she does not think of the technical details and just watches the film) are as follows:

Real-D does make a good 3D effect, but if the virtual distance of the picture is too close (things flying
towards you) it looks kind of unrealistic, you see double pictures. The light loss is significant,
the picture looks greyish (if you take off the glasses during the movie, a shade of grey goes away).
No problems with head tilting. Not the best colors, but they get better if you take the glasses off,so
it is not the projector, movie or any setting that causes that.


Dolby 3D: A much better 3D effect, no problems with channel separation like in Real-D,
but a big light loss. No color problems at all.
Really more realistic than Real-D.
The glasses could be bigger, but i know they are expensive.


Imax/linear polarisation:
The 3D effect was nearly as good as with Dolby, but much less light loss and colors do not visibly change.
Means no visible color loss.
Good channel separation, more light than Real- D or Dolby and there are no problems with things flying towards you.
Really reallistic, you think you can grab a ball that flies out of the screen.

Linear has one big disadvantage: the picture separation gets lost when you tilt your head.
I've tried that a dozen times during the film and the solution is:
If you sit comfortable in your chair, nothing happens. You will have to tilt your head so far that your neck hurts.
Then you see double pictures. Thats all for now.


Regards, Julian