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» Film-Tech Forum   » Operations   » Digital Cinema Forum   » Sony SRX-R800 phosphor laser projector (Page 1)

 
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Author Topic: Sony SRX-R800 phosphor laser projector
Alan Gouger
Master Film Handler

Posts: 463
From: Bradenton, FL, USA
Registered: Jul 2000


 - posted 11-04-2017 12:32 PM      Profile for Alan Gouger   Author's Homepage   Email Alan Gouger   Send New Private Message       Edit/Delete Post 
This is a first, Sonys new SRX-R800 series phosphor laser projector contains six laser modules and a sealed light engine. The later in theory should help maintain contrast.
Still curious if HDMI 2.0 has been added, so far no news on the inputs. 10,000:1 contrast.

https://www.sony.co.uk/pro/article/sony-digital-cinema-laser-phosphor?cmp=scl-dc-13731&SM=FB2&src=DCIN_011117_Sony

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Carsten Kurz
Film God

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From: Cologne, NRW, Germany
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 - posted 11-04-2017 03:07 PM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
Hi Alan,

They mention HDR, so you would think that the alternative content inputs support that as well. This spec page mentions 'HDMI 2'. Now, is that a typo, or will they try to escape with '2 HDMI' ports once the specs are finalized?

https://www.sony.co.uk/pro/product/4kdigitalcinemalaser/srx-r815p/features/#features

- Carsten

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Marco Giustini
Film God

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From: Reading, UK
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 - posted 11-04-2017 06:32 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
clearly the number of ports. You can see a (1) by each AES out connectors - one each.

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Carsten Kurz
Film God

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From: Cologne, NRW, Germany
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 - posted 11-05-2017 11:02 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
https://www.sony.co.uk/pro/product/4kdigitalcinemalaser/srx-r815p/features/#features

'The projector is equipped with HDMI 2 inputs as standard for presentation of alternative content.'

- Carsten

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Mark Gulbrandsen
Film God

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From: Bountiful, Utah
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 - posted 11-05-2017 04:26 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Makes no sense to install projectors with such a wide contrast range when theaters can not reproduce it. Stray light (required) and light scatter from screens limits the contrast range severely. SMPTE was at one time coming up with a standard way to measure and spec this, but it seems to have died. Perhaps there are just way too many variables.

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

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From: Annapolis, MD
Registered: Dec 1999


 - posted 11-05-2017 05:01 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Where are you coming up with all of this? The 10,000:1 is as bogus as the 2,000:1 since it is based on sequential On/Off not checkerboard with about 50% illuminated at all times BUT 2,000:1 is clearly not sufficient. There are no true blacks at that limited ratio. Getting the contrast ratio up to a real 1,000:1 would be nice (similar to film). That is going to be in the 6,000-10,000:1 ANSI so more power to them.

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Mark Gulbrandsen
Film God

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 - posted 11-05-2017 05:08 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Except that so few theaters could approach that it is a joke. Some screening rooms "might", but even that is a vague prospect. And running film (or digital) in it's optimum form is not going to net you back it's maximum contrast ratio with all other factors taken into account. Seems to me you and Neil were part of that SMPTE meeting some years back where all this was discussed.

Mark

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Marcel Birgelen
Film God

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From: Maastricht, Limburg, Netherlands
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 - posted 11-07-2017 03:11 AM      Profile for Marcel Birgelen   Email Marcel Birgelen   Send New Private Message       Edit/Delete Post 
I don't understand how any real contrast improvement can come only from a laser source.

You have to tweak your light engine too, it has to do a better job at "catching" light that's not used on-screen. So, in the case of Sony, this means better LCOS/SXRD panels.

There's the obvious trick of pushing your dynamically pushing your laser engine, just like an iris can do, but I don't really see this as a viable option for a DCI projector, as it only improves your on/off contrast.

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Carsten Kurz
Film God

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From: Cologne, NRW, Germany
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 - posted 11-07-2017 05:26 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
I guess that the typical LIP lightsource (even BLP) has a smaller etendue, thus improves contrast somewhat naturally.

- Carsten

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Mark Gulbrandsen
Film God

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From: Bountiful, Utah
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 - posted 11-07-2017 01:16 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
quote: Marcel Birgelen
I don't understand how any real contrast improvement can come only from a laser source.
Exactly! X projector is going to be stuck at what ever X contrast ratio capability the prism/lens combinations is capable of, irregardless of the light source used. It can not improve it and Imax dispensed with the prism completely because of this. When you have light paths crossing each other that actually lowers the effective contrast ratio the system is capable of. This is why lenses some times utilize light baffles to eliminate back reflections inside the lens which would lower the effective MTF of the lens. D-Cinema lenses utilize some very ingenious series of light baffles so they maintain the highest MTF possible!

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 11692
From: Annapolis, MD
Registered: Dec 1999


 - posted 11-07-2017 01:28 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Actually, doing a bit of research, Laser Phosphor CAN improve its contrast ratio a little bit due to the lower etendue. Barco is claiming around 20%. I have not verified their implementation to prove/disprove it. But the people I trust that know about such things back up the potential of Barco's claims.

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Marcel Birgelen
Film God

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From: Maastricht, Limburg, Netherlands
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 - posted 11-07-2017 02:06 PM      Profile for Marcel Birgelen   Email Marcel Birgelen   Send New Private Message       Edit/Delete Post 
Well, I tend follow Mark on this, unless I'm missing something here:

A light source with a smaller etendue should increase the efficiency of the light source, since there's less light getting lost in reflectors, lenses and other optics trying to focus the light on the DMD/LCoS imager. Yet, a more efficient light source alone doesn't imply a higher contrast in the image.

Besides the quality of both the lenses and the prisms, the contrast is primarily going to be defined by the quality of the imagers, the DMD or LCoS type devices. More precisely by the difference between the amount of light they're able to reflect towards the screen and deflect away from hitting the screen. A 100% perfect system should be able to control this per pixel and should reflect 100% of all the light in an on-status versus 0% of all the light directed at it in an off-status.

One thing where I think laser could help is, because the laser light in itself is more coherent, there will be less "non-directional" or "stray" light hitting the imager at an odd angle and causing leakage into the image at large. Although I'm pretty sure this effect exists to some extend, I have no real idea how much it affects current designs. There might also be other solutions for this than lasers, like polarizers. Obviously those will not enhance the efficiency of the light sources.

Another thing could be the lenses and prisms themselves, but this only applies for 3P/6P laser systems. The monochromatic aspect of the primaries will probably make it easier to correct for chromatic aberration, since you only have to account for three very discrete wavelenghts. This however, should increase the sharpness of the image, not so much the contrast.

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Mark Gulbrandsen
Film God

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From: Bountiful, Utah
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 - posted 11-07-2017 07:43 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
Someone needs to step up to the plate and get rid of all the glass, meaning the Prism itself. It can't be THAT difficult, except getting around the Imax patents. Hey, others have done THAT over the years. LCD projectors have never used big prisms in them that I have ever encountered and they do their tricks with just high temperature plastic frames. A precision machined frame supporting high end front surface and partial mirrors is long over due in regular cinema. Then the laser light does not have to be combined before hand. Pump in each section of light to it's appropriate DMD and back out and combine it going into the projection lens itself. Not unlike the reverse of a three CCD TV camera.

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Adam Martin
I'm not even gonna point out the irony.

Posts: 3629
From: Dallas, TX
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 - posted 11-07-2017 10:13 PM      Profile for Adam Martin   Author's Homepage   Email Adam Martin       Edit/Delete Post 
You seem to know a lot about this, so why don't YOU do it? Then we can all sit around bitching and moaning about your device and tell stories of how the equipment WE use has never had a problem. [Razz]

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Carsten Kurz
Film God

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From: Cologne, NRW, Germany
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 - posted 11-08-2017 06:36 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
LCD projectors do use prisms as well.

You can always increase contrast easily by sacrificing light. But who wants to do that, other than for screening rooms/post production or simulators?

There are other ways to recombine light, but prisms do not only have disadvantages, they also have a great advantage - stability, once built, there is no drift in registration. The Laser IMAX solution is very expensive in order to reduce that issue. And the Kodak/IMAX patents may prevent other companies from doing it commercially.

There are some references that the maximum achievable on/off contrast for current DLP imagers is around 10.000 to 12:000:1. While Laser IMAX comes close, other manufacturers slowly seem to achieve something in the 3000-5000:1 ballpark with their LIPs. Sony quotes a very solid 8000:1 for their UHP SRX-R 5xx series. I guess it wasn't that complicated to improve this towards the 10.000:1 they now quote for their phosphor laser - even their (non cinema) SRX-T615 UHP counterpart is quoted with 12.000:1. Dolby Vision/Cinema is a bit different as it not only cares about sequential contrast improvement with it's (expensive) 'local dimming' approach.


With exit/emergency lights, auditorium design and patrons clothes and faces bouncing light back to the screen, I guess it doesn't make sense to achieve much more than 5000-8000:1 on the projectors part. How that translates to in-picture/ANSI contrast for the different technologies is an interesting question. Usually, more work is spent on analyzing high end home cinema projectors than in evaluating DCI machines.
The Barco LHC machines seem to target these realistic numbers. Barco started to quote sequential and ANSI contrast figures for their RGB laser machines. From these numbers, the LHC machines look very promising. I hope they also improve on the speckle issue.

At some point, self illuminating screens will take care of that issue as well, and also improve in-picture/ANSI contrast greatly.

- Carsten

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