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

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » The latest "what is AMC doing wrong" query: high black levels (Page 2)

This topic comprises 3 pages: 1  2  3

Author Topic: The latest "what is AMC doing wrong" query: high black levels Steve Moore Expert Film Handler Posts: 211 From: Leeds, West Yorks, UK Registered: Apr 2008 posted 08-16-2014 11:08 AM                     Any Sony installs I have seen look somehow, for want of a better word "fuzzy"; strange artefacts and an almost misty look to the picture. I think the old Christie Series 1 from what I have seen out performs in sharpness and wow factor; certainly considering that they are 2K. But that might just be the few sony's ive seen; I can't speak for them all  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 08-16-2014 11:21 AM                     They never seem to get Green right...the color just looks "fake" for lack of a better description. I have NOT compared all models, however.  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 08-16-2014 12:59 PM                     I've never noticed that, I'll pay more attention next time. Corrected colours are always spot on, but it may be something else, after all colours are not just gamut. Make sure you reset the correction, even though the projector is brand new. I have seen instances where the colour looked "fake" during calibration and resetting the calibration brought it back to what I was expecting. I had the opportunity to compare a DLP to a 320 a few weeks ago. I managed to run the same clip from a feature and the 320 was way better in terms of contrast ratio.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 08-16-2014 01:15 PM                     DLP's contrast ratio is not their strong suit.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 08-16-2014 01:47 PM                     Granted, you shoot an image on a screen, coming out of a 320, which is less than 40 ft wide and a throw over 70 ft using an USHIO 3k bulb and you do have a very nice picture.  |  IP: Logged Connor Wilson Expert Film Handler Posts: 190 From: Sterling, VA, USA Registered: Jan 2011 posted 08-16-2014 04:04 PM                     Last movie I saw on a Sony unit was Guardians of the Galaxy, in 2D from a 320 projected on a common width screen. It wasn't as impressive as the same movie from a Barco unit in Dolby 3D, common width screen. I actually compared (not directly) The Lego Movie between a 515 and a 320 in the same complex, both in 2D. The 320 had a misty look, while the 515 was crisp and clear. I was impressed by 515 married with RealD 3D when I went to see Dawn of the Planet of the Apes. The screen was common height, and it was a shorter throw. And this was an AMC where they played the "See more trailers..." snipe before the trailers and the Coming Soon snipe after the trailers.  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 08-16-2014 05:01 PM                     You can't compare a 2D with a 3D picture! The 515 has a massive contrast ratio and a very low black level. But to be honest I don't see the 'mist' on the 320 I see around. I would be more probe to blame the auditorium (bright walls, dirty porthole, dirty lens).  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 08-16-2014 05:47 PM                     Doesn't the 515 have about a 10,000:1 contrast ratio?  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 08-16-2014 06:03 PM                     8000:1 on the datasheet  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 08-16-2014 09:21 PM                     And with a checkerboard pattern?  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 08-17-2014 05:34 AM                     I've never tried that, but you'd need a perfectly black auditorium to take a meaningful measure. You could turn the meter towards the projector, but my meter does not allow that. In the real world I've measured on/off 4000:1, but, again, the auditorium was not pitch black.  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 08-17-2014 06:21 AM                     Not a single projector in the world goes above 1:600 to 1:700 with a checkerboard/ANSI measurement, and even that only under experimental/bat cave conditions. All contrast numbers above that are on/off or 'sequential contrast'. It's quite typical for pro and home projectors that DLPs shine in ANSI, but suffer in sequential contrast, while e.g. for LCoS/SXRD the achievable ANSI is lower and the sequential contrast is higher. This is not an exclusive ANSI/sequential behaviour - these weaknesses or strengths operate through all typical varying image types/amounts of bright/dark in images. So, the darker the image, e.g. night scenes, the better the SXRD will perform, while in evenly, bright lit scenes the benefits of the higher ANSI contrast of the DLPs come out. It's just that you don't perceptually weight an ANSI/in-picture contrast difference between say, 1:300 and 1:500 as much different, while an on/off contrast of 1:1500 or 1:5000 makes all the difference. It probably wouldn't be so important if not film makers nowadays would choose to underlight scenes or use available light a lot more than they used to 20-30 years ago. The amount of image parts lying in shadow is much higher nowadays. And that plays towards the need for higher on/off or sequential contrast, because you don't want large areas being ripped up into greyisch-brownish noise. Something seen very often with the S2k and 4k DLP chipsets (lens quality and apertures used/not used being an issue as well). Everyone knows that even a mediocre LCD presentation projector can look good with a nice, bright, evenly light picture. The trouble comes with the shadows and high contrast imagery. Most manufacturers, even in the Pro business, prefer to give on/off contrast numbers, simply because they are always higher than ANSI contrast numbers. ANSI/checkerboard is only one defined measurement method for in-picture contrast. You could easily get very different numbers if you change the measurement pattern into something with different areas/amounts of black and white. So, as a matter of fact, the in-picture contrast of every projector is different for all occurring images/footage that runs through the projector. It's a moving target. On/Off contrast is independent of image type/footage, but is not really a practical measurement, but gives an indication on the achievable 'darkness' a projector can produce under static conditions. Some DCI-type DLPs can be modified with aperture plates in the projector and/or in the lens. I think you can increase on-off contrast towards something like 1:3000, but it maxes out around there (ANSI will also improve). But it eats a lot of light, so this is nothing for the bigger screens. In most real-world conditions, due to ambient/exit and emergency lighting, achievable ANSI/in-picture AND sequential/on-off contrast is much lower than above quoted numbers - typically not even higher than 1:100 to 1:200. - Carsten  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 08-17-2014 07:12 AM                     I firmly believe that both figures have to be taken into consideration. on/off contrast (which for a 14fL picture basically tells us the black level) is important but ANSI is important as well. If ANSI is low, the black level figure will disappear as soon as a candle appears on screen. I did not know that SXRD were lower in ANSI. But as you say it is not easy to measure - should do that in a bat-cave to have meaningful results. As a reference, high end home theatre projectors can achieve 30.000:1 on/off contrast ratio. Dark sequences look amazing, but bright ones look so washed out.  |  IP: Logged Ken Lackner Phenomenal Film Handler Posts: 1907 From: Atlanta, GA, USA Registered: Sep 2001 posted 08-18-2014 10:32 AM                     quote: Monte L Fullmer If Sony would pick up on BARCO's CLO system, these lamps may have some decent light output throughout the life of the lamp. But Sony's blast theirs hot from the beginning which causes them do decay quite readily. I'm not sure where you got that from, but it is entirely false. Sony projectors most certainly do have a method of maintaining even light output by automatically adjusting the current throughout the life of the lamp. Of course, as with any projector, to take advantage of this feature requires headroom. That is, if you must run a brand new lamp at 95% or 100% to get the required light on screen, you have no room to increase the current and the light output will definitely decrease over time. If you encounter a projector that is running a lamp at 100%, that's because the installer set it up that way. (Probably because the screen is too big for that projector, but that's not the projector's or installer's fault.)  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 08-19-2014 05:23 PM                     Indeed, both the 320 and 515/510 have switchable direct power, or constant luminance lamp control through an internal sensor, just like the DLPs do. - Carsten  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1  2  3

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.