my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » laser phosphor projector vs xenon (Page 3)

This topic comprises 5 pages: 1  2  3  4  5

Author Topic: laser phosphor projector vs xenon Tom Bert Expert Film Handler Posts: 134 From: Belgium Registered: Apr 2010 posted 06-19-2017 04:29 AM                     On this topic: "I see in their literature that for the "C" series it is "up to 2400:1." The "B" series is listed as 2400:1. Whatever they are doing it isn't inherent in the LP technology." The SLP/CLP/BLP contrast ratio spec IS higher than on the respective Xenon-equivalents. This is thanks to the smaller etendue of the LP lightsource. Less stray light from the start --> higher CR at the end On the topic of XYZ colors vs spectrum: this is the whole domain of "metamerism". In a nutshell: - the theory behind measuring and quantifying colours (= putting a XYZ- or xyY-number on something that is inherently a continuous spectrum) dates back to 1931: https://en.wikipedia.org/wiki/CIE_1931_color_space - the light sources to build up that theory where broadband. When applying them to narrowband sources (laser, but also LED or OLED) tweaking of the formulas is required - the problem is that broadband sources by nature average out the integration in the math (across gender, age, race,...); not something trivial when trying to the same for narrowband (the 'filters' in my eyes are slightly different than in your eyes)  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 06-19-2017 07:10 AM                     And yet none of the other LP manufacturers claim a higher contrast ratio. I get the higher efficiency but not the higher contrast.  |  IP: Logged Harold Hallikainen Jedi Master Film Handler Posts: 906 From: Denver, CO, USA Registered: Aug 2009 posted 06-19-2017 08:40 AM                        Tom, GREAT to see you and your expertise here! On stray light and xenon, can there be a lamp enclosure that prevents or minimizes stray light? Harold  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 06-19-2017 03:11 PM                     Tom, Would you get the same contrast improvement by retrofitting an existing machine?  |  IP: Logged Pietro Clarici Expert Film Handler Posts: 136 From: Foligno (PG) Italy Registered: Sep 2008 posted 06-20-2017 07:17 AM                        Tom, Can you comment on your high-contrast smart laser range that was pre-announced today by Ymagis/EclairColor and just give ballpark contrast and brightness numbers? Looks like they could be of extreme interest to independent exhibitors like myself who would like to transition from S1 and S2 projectors to 4K laser, but could never afford a flagship LHC machine. Thanks!  |  IP: Logged Tom Bert Expert Film Handler Posts: 134 From: Belgium Registered: Apr 2010 posted 07-24-2017 08:02 AM                     On Q1: "can there be a lamp enclosure that prevents or minimizes stray light?". It is possible to apertures in the light path: that boosts contrast, but also sacrifies brightness. No free lunch I'm afraid On Q2: "Would you get the same contrast improvement by retrofitting an existing machine?". Yes, same improvement. On Q3: "comment on your high-contrast smart laser range". Too early to share specs I'm afraid.  |  IP: Logged Connor Wilson Expert Film Handler Posts: 190 From: Sterling, VA, USA Registered: Jan 2011 posted 09-17-2017 02:46 PM                     I had my first Laser Phosphor movie experience last night, at the brand new Landmark at 57 West in NYC that opened Friday. I don't know what brand was behind the projectors, but Landmark advertised the use of laser projection even before the venue opened, without giving any specific details. Judging by the type of theater and the history of the chain, I'm guessing they are Barco Smart Laser LP projectors. My show was at Screen #6, which I would assume is one of the bigger ones, but the screen is nowhere near as massive as Alamo Drafthouse Downtown Brooklyn theater #7. In fact, it's one of those awful "mask-less" screens with rounded edges in a fixed 1.85:1 ratio. So yes, it was like watching TV in public, my feature was mother!, a film which I looked up almost zero information on beforehand, so the awfully letterboxed Paramount logo gave me a middle finger to my expectations. Yes, the Paramount logo, and not some windowboxed Flat trailer in a Scope container before. The opening trailers were presented in Flat, with some letterboxed Scope trailers in the mix, even the now-classic Landmark Theaters logo animation filled up the entire screen in it's simplistic grandeur of text and rainbows. But, of course, this isn't the thread to discuss showmanship gone wrong. My first impressions of the visual quality of Laser Phosphor was a colorful and striking trailer for Woodshock. The fidelity of the colors and cinematography almost felt glossy and surreal, like a very polished and clean glass window to another world, as if the splendor of cinema and special effects were perfectly translated as a live performance. And a big part of my impression was due to Woodshock's production values itself, as the following trailers, two documentaries and a period piece, weren't up-to-speed. I'd argue the other three trailers looked no better than it would on any DLP or SXRD projector. I had previously only seen the trailer to Woodshock on a DLP, the difference it makes on the LP is very impressive. Back to mother!, I can't tell if the graininess of the feature had something to do with laser speckle, or the 16mm negative it was shot in. The Paramount logo that opened the film had some nasty speckle to it, and having only seen mother! once in that particular environment, I don't know if grain was added to the Paramount logo in post, but I do know the colors were graded. Also, it's important to take note that between the trailers and feature, the projector had to switch from Flat to unmasked Scope, so that may add something to the artifice. As far as contrast ratio is concerned, the black bars on the screen were bright as day, considering this is as pure of black you may ever get in D-Cinema, it does not place LP above xenon for me. And no, I did not notice "speckle" in the trailers as intensely as I did in the feature. So the film could be grainy, or scope mode in screen #6 is "speckle-y."  |  IP: Logged Harold Hallikainen Jedi Master Film Handler Posts: 906 From: Denver, CO, USA Registered: Aug 2009 posted 09-17-2017 03:29 PM                        Is speckle possible on a laser-phosphor projector? I look at these as a fluorescent light using a laser to excite the phosphors instead of a mercury vapor arc. I think it should be relatively broad band like xenon, but with peaks at different wavelengths. Harold  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 09-18-2017 03:13 AM                     Current phosphor laser projectors usually use two lasers or at least two separate laser sources (consisting of multiple diodes), one that excites the phosphor and the other one as a direct source for the blue component. I'm not entirely sure if Barco also uses the blue component as a direct light source though. So, in the red and green components, you will not have any speckle, but I guess the blue component is somewhat prone to speckle. Then again, I didn't see any speckle in the DP2K-8SLP, even when projecting a 100% BLUE image and neither in a pro-consumer oriented projector from Epson, the LS-10000. The LS-10000, most definitely has two separate laser sources.  |  IP: Logged Tom Bert Expert Film Handler Posts: 134 From: Belgium Registered: Apr 2010 posted 09-19-2017 05:58 AM                     quote: Harold Hallikainen Is speckle possible on a laser-phosphor projector? I look at these as a fluorescent light using a laser to excite the phosphors instead of a mercury vapor arc. I think it should be relatively broad band like xenon, but with peaks at different wavelengths. It is theoretically possible, since some direct laser light (blue, in case of 'normal' LP. blue and red, in case RB LP) still hits the screen. However, since it is only a -small- fraction of the total luminance, the perception is much lower than on RGB laser. We have 2000+ LP installs in the field on screen gains going from 1.0 to >2.4... and had no complaints on speckle so far  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 09-19-2017 11:10 AM                     Since the human eye is least sensitive to blue the speckle that may be created there if they are using it as a direct light source probably wouldn't be so noticeable. Its difficult enough to see a stuck blue pixel or two... Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 09-19-2017 06:32 PM                     Normally, the Blue-laser goes through a diffusing wheel so I question just how much of a laser the light is by the time it enters the integrating rod. That said, i know that NEC has a service mode (for when the cover is off) where they shut off the blue-only laser and only let the one that goes through the phosphor wheel continue so I guess it must still be laser-like enough.  |  IP: Logged Amrik Kailey Film Handler Posts: 2 From: Punjab, India Registered: Oct 2017 posted 10-21-2017 03:54 AM                     Here is a study/facts regarding xenon,laser phosphor or RGB pure laser by Christie Digital itself http://www.lamptolaser.com/index.html enjoy  |  IP: Logged Frederick Lanoy Film Handler Posts: 88 From: North of France Registered: Aug 2009 posted 10-21-2017 04:39 AM                     It looks more like marketing with some technical explanations than facts to me.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 10-23-2017 03:17 PM                     quote: Steve Guttag And yet none of the other LP manufacturers claim a higher contrast ratio. That's because all existing systems excepting Liemax use a prism system for the light engine. And that is where the contrast is lost. Diffraction in the prism's themselves and then the light passing by itself again more than once. Coatings only help so much here. Not until one of the D-Cinema manufacturers is smart enough to dispense with all the thick glass will things ever get better in that realm. I just hope Liemax doesn't own all the patents on doing that. Mark  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 5 pages: 1  2  3  4  5

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.