The Ultimate 3D projection system: A Practical Discussion Thread - Page 9

Big news - I received tonight the new firmware update for the 3DXL to enable 24p output for Bluray 3D.

Travelling right now, but will test this out before the weekend is over!

Also, have ordered samples of a variety of 3D screen materials, but in the meantime I have ordered replacement fabric for my existing BD2 frame. So hopefully next week I'll have the SI Solar 1.3 in house so that I can complete testing of the final configuration.

Got word from Optoma that they have tested OK for 720p and 1080p side-by-side by using the "SBS Mode" button. And DirecTV 1080i SBS is detected automatically.

Personally, I have Bluray 3D being demuxed now with two 3DXL units - one for the Left and one for the right - feeding two projectors. All working perfectly.

Also - I'm now one step closer to the ultimate 3D system now, as I loaded the new firmware update today on both 3DXLs and I'm now getting 24p OUTPUT FROM BLURAY 3D!! Yes...

Also, I have a new SI Solar 1.3 screen arriving this week, which is supposed to retain circular polarisation, plus various other screen samples to test and compare.

Once the new screen arrives, I'll finally be able to watch the first movie on this setup!

We're almost there!

EDIT - by the way, watched a lot of "How to Train Your Dragon" Bluray 3D tonight, split into two 24p streams by the 3DXL boxes - the frame interpolation in the RS40 units made the 3D output SO SMOOTH! Each eye was getting 48p projected at 96 hz. Just dying for this screen to arrive to have the first viewing.

EUREKA!!!!

I have stumbled onto the SOLUTION for the JVC projectors giving off HORIZONTALLY polarised light!!!

If anyone read some of the testing posts I made, I found that the horizontal polarisation of the JVC units meant that standard RealD glasses would not function in an optimal manner.

You see, all circular polarisers have a layer that is actually a linear polariser built in. And, for the best extinction ratios, the linear component in the glasses must be 90 degrees offset from the linear component in the projector lenses.

In the case of our system here, RealD glasses' linear component are Horizonal, and my projectors are ALSO horizontal, meaning that to get the best extinction, I either had to hold the RealD glasses sideways, or hold the projector sideways (chuckle), neither of which was what I wanted. (RealD projectors in the theater are vertically polarised before the circular polarisation is applied).

SOoooooo - the Solution???

It turned out to be very simple, and the light bulb went off after I did some more reading about the physics of the optics involved.

You see, if you combine two quarter wave plates (the film used to make the circular filters), you can create a half wave plate, which is COMMONLY USED to change the orientation of polarisation in lasers and projectors!!

That means I can EASILY convert the HORIZONTAL polarisation of the JVC projectors into VERTICAL!!!

MAN am I happy right now!!! I will be able to use my stock of RealD glasses after all, and no custom work will be necessary.

AND ANOTHER THING!

Being able to rotate the polarisation of the projector now means that we can ALSO use a LINEAR polarised passive system on these JVC units, not just circular.

This really changes all my considerations.

We can use a half wave filter plate like a mentioned, to change the JVC's horizontal polarisation -45 degrees for one eye, and +45 degrees for the other. It will THEN work with the STANDARD 135/45 degree linear glasses available anywhere.

SWEEEEEEET........

I will be adding linear passive back into my system options and testing that here also. Will also edit my opening posts to reflect the new info.

Too true. Based on what I now know, I could only recommend a projector where either there is no polarisation, or it is linear polarised with all colors at the same angle.

I think most projectors should fall into that category, but testing the polarisation is a critical step.

But I am just so happy that I can do linear with these without losing much light - throws out all the estimates we all discussed at the start of the discussion about losing 50% of the light - we will end up keeping almost all of it.

Interesting - it appears that Infitec are making a big announcement this week about a new lense design. Don't know if that means something that will perform better with our projectors, or if it is just a commercial announcement. But it may be something to watch.

That certainly sounds interesting - a lot will depend on whether something that small and simple sounding will be able to recognize and separate all the various 3D formats.

For Bluray 3D, the task of demuxing is dead-easy, as it truly is mutliplexed and follows a cut and dry standard - but other SBS and TAB formats are not truly multiplexed and need to be interpreted or manually directed.

But the more options the better.

Ok - I was unable to resist the temptation to put everything together before the arrival of my new 3D screen...

Completed the assembly tonight with a crude stacking methodology (ie the pjs are literally "stacked" on top of each other), and fired them at my BD II, even tho I know the BD II is not retaining proper polarisation.

The results were far more impressive than I thought! All surface structure on the screen disappeared. Ie the sparklies disappeared, and the terrible surface distortions were gone too. Very interesting.

However, because of the loss of some circular polarisation on the BD II, there was significant ghosting in some scenes.

Nevertheless, I watched A LOT of films tonight in 3D. Very nice.

I took a few shots without the RealD glasses on the camera...

And let me tell you... This setup is BRIGHT!!!

I wish these pictures could do the scenes justice. I picked shots where the scenes were just FILLED with depth - glass, leaves, dust, debris filling the air, and multiple planes of scenery... but of course, none of that can be seen in a 2D snap - just lots of double image.

I cannot stress enough how BRIGHT the image is - I estimate that each eye is getting three times the light that they are when I do single projector with shutter glasses, given the black frame insertion and the flashing.

Only issues remaining are (1) Screen is not circular polarisation compatible, and new screen arrives this week (2) Denon 4311CI does not seem to be giving the identical output on both it's HDMI outs, so the new HDMI splitter arrives this week also.

Once the HDMI splitter is in, I will turn on Frame interpolation so I can double the real frames and make the films much smoother - very important in 3D, IMO.

Finally - after discovering that I could get a wave retarder built-in to my projector filters and rotate the polarisation of the RS40s, I have decided to go with a linear polarised system over the circular. The linear is supposed to have better extinction ratios, which is a number one priority for me at this time.

So I've ordered a set of Advisol filters through their dealer - they are custom building them to include the wave retarders and rotating the polarisation of each projector so that they will project a standard 45/135 degree linear 3D picture that most linear glasses are built for.

The new filters should be here soon, and in the mean time I'll be playing with the circular setup, so I'll have test results for both.

Stoked!!!

You would be fine doing a dual projector setup like this as long as: (1) You test the pj to see what the situation is with the light polarisation, per the first page of this thread, and (2) the projector can accept a 1080p24 signal and convert it to whatever it displays

Now, my GUESS would be that the light is "probably" unpolarised, on that DLP unit, but there is no substitute for testing yourself (and maybe posting results here for others)

However, I don't know if that unit can accept a 1080p24 signal, in looking at its specs online, there is nothing concrete. I don't know if we can tell the 3DXL to output 720p60 as a workaround, so you'd have to get more info on the pj, or test it with a Bluray at 24p.

Other 3D formats are likely to be displayed at 60p or 60i and may be less of a worry, perhaps, but testing and investigating a speficic unit to ensure input flexibility is important.

Hope this helps!

Definitely worth him checking, yes.