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Topic: laser projection

Steve Guttag
We forgot the crackers Gromit!!!

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

posted 12-27-2014 04:00 PM

Again...presuming one is considering a dual projector system...the screen in question is probably sufficiently large to make it worth while. Naturally, it isn't the solution for all screens. A hope of laser technology is the ability to use a single laser projector for most large cinemas. The dual-projector thing is normally for very large screens, particularly with 3D. A format that I, personally, hope continues to die away. The numbers I recently saw at a local theatre show that it is making less money and definitely drawing fewer patrons than 2D...by a very significant amount (drawing less than 20% of the 2D shows)

As for Christie...the lamp alignment is second to none...it does a VERY good job and the duo convergence is not something I've had to work with...just seen it demonstrated...it was spooky good. Note...if one needs to realign it on any sort of regular schedule...if your theatre is too pathetic to have someone reliably do that with a push of a button...then automate it...that wouldn't be rocket science either.

Don't be so fast to condemn something you haven't personally worked with as not real-world worthy just because it may not work in your world. We definitely have the technology at our access in this day and age to minimize, if not eliminate, most human involvement in repetitive tasks.

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Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 12-27-2014 04:22 PM

quote: Marco Giustini
After all, the RealD XL unit could be moved away in less than 2 seconds but as Steve points out it is seldom done by theatres.

There are multiple reasons why this, unfortunately, is the standard:

- Mixed bookings of both 3D and 2D movies in the same theater.
- Getting it out of the way isn't hard, putting it back in and getting the convergence of the two images right is another thing...

Both are lame excuses, but real world scenarios.

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 12-27-2014 06:20 PM

Nonsense. At least for Real-D XL. There are XL movers from Strong and MiT to automate the DLP experience. For Sony, MiT has one that will, at least, move the polarizers out of the way. But yes, it will still have the stupid dual 2Kish image left.

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Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 12-27-2014 07:06 PM

No, it's not nonsense, rather unfortunately. It's not that I agree with such practices, but it happens and those are the main reasons why it happens.

I know about the RealD XL movers, but at least around here, they aren't common. It's all about cutting corners, mostly at the wrong end though. Instead of investing in a proper mover, they rather drive up the lamp to somewhat compensate for the lost brightness in 2D...

quote: Marco Giustini
I am not familiar with the Christie Duo though, so I'm assuming that converging the projectors is not a problem. But does it do it automatically or does it require any human action? In the latter, even though it's just pressing a button then it's out of the question.

Basic realignment for DuoAlign can be automated via macros. It uses a CCD camera together with a bunch of calibration paterns for the final steps of automatic alignment.

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Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007

posted 12-28-2014 06:05 AM

Steve,

I believe you misunderstood me. If it was for me, all cinemas would have the best projection and sound system available and a skilled technician on site doing daily checks on everything. That is the only way I know to run a cinema.

I do not condemn anything, I'd love to work with a dual projection system or with whatever you can think of. But I can see what happens around me and my comments are based on that.

On most of the installations I see around the Christie LampLOC is never used. Why? Because they don't care/nobody is in the booth/they don't know about that - take your pick. Even adjusting picture focus and volume can be a problem sometimes.

And if the chain is leaving the XL unit in all the time, are you really expecting that they would send someone to check the convergence of their dual projector system every now and then? Or - even better - that they have someone capable of evaluating the system and adjust it?

Again, don't get me wrong, I am not discarding the DUO or anything else. I am just imagining those systems in my world and I can see that they're not going to work!

Marcel, the XL convergence will NOT change when the unit is moved in and out - unless you slam it to the stops! It is a 5 seconds job but if you don't have personnel available, you can't risk to start the next 3D show with no 3D. As you point out mixing 2D/3D shows does not help.

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Carsten Kurz
Film God

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

posted 12-28-2014 08:42 AM

quote: Marco Giustini
I was told that Dolby 3D on 6P lasers is "close to the physical limitation of 3D" which is 50%. I was not given a real world figure though. Where did you take your numbers?

I took these numbers from a current Barco Whitepaper on their laser technology.

http://www.barco.com/~/media/Downloads/Presentation/NAB14_BARCO%20pdf.pdf

Also the general energy efficiency is not SO much better than for Xenon. Don't know if they even include the power needed for the chillers into their calculation. Okay, this is their first commercial laser product, so they may be able to improve that later.

While the Christie solution is similiar, so far I haven't seen any Dolby 3D branding for the Christie 3D setup. It seems to me that laser based 6P spectral separation is not covered by the existing Infitec patents/Dolby license. So it may be that Christie can do without Dolby. The Christie Duo solution does near-perfect automatic alignment. Aside from the mirror, it is a bit similar to the IMAX automatic alignment system. You need both projectors to have a Christie IMS/IMB installed though, as part of the alignment takes part in the image processing part of the IMS (as in the IMAX raster processor).

- Carsten

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Steve Guttag
We forgot the crackers Gromit!!!

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

posted 12-28-2014 10:49 AM

I did understand you and while you can certainly point to theatres around you that won't move a Real-D XL out of the way...I can point to many, many that will and others that have purchased some form of automatic mover to ensure that the task gets done. Likewise on the Christie LampLOC. Remember, I have "real-world" theatres too...they are not all screening rooms and special venues.

I took the comment regarding Sony's 2D/3D thing to mean that it wasn't just the polarizers but the physical 3D versus 2D lens itself...hence the convergence realignment once the dual lens is reinstalled. That the comment was not directed towards a convention RealD-XL.

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Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007

posted 12-28-2014 06:28 PM

I honestly hope you are right and I am getting a little too pessimistic - honestly. There are lessen and lessen cinemas/theatres doing "film" right nowadays. Every now and then I think of one where I would like to pay and watch a film myself and I usually struggle to come up with a place.

2D/3D: I didn't realise we were talking about Sony? If the subject was Sony, convergence does not really matter too much. If the cinema cares enough to swap the lens - with the 515 and lens changing table it is in fact quite easy - when the 3D lens is in, it means the cinema is showing 3D. And as Steve pointed out, alignment with 3D content is not critical.

But I still have on my mind this 'projectionist' saying 'we can't be bothered swapping lens, we just put a 3D cue and it's ok'.

Again: I honestly hope I'm just getting too old and too pessimistic [Wink]

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Marcel Birgelen
Film God

Posts: 3357
From: Maastricht, Limburg, Netherlands
Registered: Feb 2012

posted 12-28-2014 06:56 PM

quote: Marco Giustini
Marcel, the XL convergence will NOT change when the unit is moved in and out - unless you slam it to the stops! It is a 5 seconds job but if you don't have personnel available, you can't risk to start the next 3D show with no 3D. As you point out mixing 2D/3D shows does not help.

Well, many multiplex operations here run more or less on auto-drive. Maybe there's someone around with just the most basic level of knowledge, but there's often nobody around to go swap non-automated polarizers after/before every show. So, those things will, in many cases, just stay where they are...

Convergence of RealD XL is an issue, if you keep getting the unit out and putting it in after each show, especially if done in a hurry, it will start to suffer.

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Marco Giustini
Film God

Posts: 2713
From: Reading, UK
Registered: Nov 2007

posted 12-29-2014 03:20 AM

Marcel, I believe we are on the same page.

About the XL unit, I don't doubt the alignment will require a little tweak after a while, what I am saying is that it won't require a technician EVERY time you move it in and out.

And anything done in a rush is likely to have an awful outcome!

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Dave Macaulay
Film God

Posts: 2321
From: Toronto, Canada
Registered: Apr 2001

posted 12-29-2014 10:05 AM

It takes a good whack to throw the XL out of alignment much but "best possible" is still not good enough for 2D, if you care about presentation quality. Fine for 2D trailers in a 3D show but shabby for a 2D feature.
If your staff is slamming the XL in and out (assuming the rails are lubed properly so the unit slides smoothly and easily), they need some attitude adjustment - or you need some new staff.

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