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

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » Chromacity variation

Author Topic: Chromacity variation Lucas Iaccarino Film Handler Posts: 37 From: capital federal, buenos aires, argentina Registered: Feb 2015 posted 02-16-2018 01:52 PM                     Hello; I`m having some issues with a Screen at a Venue. I made some tests, and I found out that the white is not the same values across the screen. I`m sure that the left side of the screen is greenish that the right side, that seems more reddish. I`m not sure if is because the luminance is not uniform - 9 fL (Left) VS 10 fL (Right) - a calibration issue - The convergence test showed that the Blue DMD is a little offset - or something worst, like a dying engine. I´m attaching a cellphone picture, but it can be lightly notice. Thank you!  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 02-16-2018 03:20 PM                     Another stunning example of people mistaking their Sonys for a DLP. Lucas - this projector is not a DLP, as it is an industry-known fact that only Sony systems exhibit such behavior! Honestly - what type of projector is it, and how old is it? Has it ever been serviced/cleaned? - Carsten  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 02-17-2018 04:37 PM                     Yes Sony projectors tend to have odd color artifacts. For S2 DLP projectors the TI ICP can use a "SCC_LUT" file that corrects for color shift across the image. It is a pain to create but not impossible. I think most use a default file with no correction, a Barco .69" chip projector comes with a factory generated file for its light engine.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-17-2018 05:11 PM                     Barco 4K light Engines also come with a LUT-SCC file (downloadable if you have the LIGHT ENGINE serial number (not the projector serial number). As for creating one on a Barco, they have a wizard so if you have a good meter (PR-655 or better) then creating one isn't that hard either.  |  IP: Logged Lucas Iaccarino Film Handler Posts: 37 From: capital federal, buenos aires, argentina Registered: Feb 2015 posted 02-19-2018 10:13 AM                     Hello, thanks for the answers! I`m familiar with DLP technology and I searched across internet before making this post This is a Christie CP2220, I`m not sure how old it is but not more than 4 years and being deeply cleaned 2 weeks ago. I also thinks it`s about color correction, and probably a default file being used. Dave, do you think it`s possible to make a LUT to correct this? Do you have any material to read about this? Thanks agaiN!  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 02-19-2018 11:25 AM                     On a CP2220, I suppose a misalignment is the cause of this issue, maybe that happened during the recent cleaning. Did you notice this issue already before the cleaning, or was the cleaning ordered because of this issue? - Carsten  |  IP: Logged Lucas Iaccarino Film Handler Posts: 37 From: capital federal, buenos aires, argentina Registered: Feb 2015 posted 02-19-2018 11:48 AM                     I didn`t check it before the cleaning... Do you mean that maybe the DMD are misalignmented because the cleaning? Thanks!  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 02-19-2018 12:58 PM                     Maybe the integrator rod, cold mirror, or some of the relaying lenses. I'd try to contact Christie about this - I wouldn't trust an ordinary tech on this. I think there was a discussion a while ago about reasons for DLP color uniformity issues, calibration LUTs etc., if I remember right, only Barco allows to create them yourself, and they may not even be available for 1.2" or 0.98" DLP units, only for 4k and S2K. http://www.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=003178#000005 - Carsten  |  IP: Logged Lucas Iaccarino Film Handler Posts: 37 From: capital federal, buenos aires, argentina Registered: Feb 2015 posted 02-19-2018 01:14 PM                     Thanks you very much! I will check it out and let you know Regards!  |  IP: Logged

All times are Central (GMT -6:00)

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.