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

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » Gamma setting for "alternative content"

Author Topic: Gamma setting for "alternative content" Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 10-03-2010 05:15 PM                     An interesting question has been posed on another site regarding the gamma setting of DCinema projectors when running NON-DCinema content. The Gamma for DCinema content, as defined in DCI spec is 2.6 However, that is not the case for HDTV or other non-DCinema content. It is typically 2.2 - 2.35. Failure to have the proper Gamma will result in either lost black detail or washed out images. This is presuming too that one properly sets their color space too. So how are you people setting up your DCinema projectors when running non-DCinema content? Steve  |  IP: Logged Daniel Morez Film Handler Posts: 21 From: Hollywood, CA, USA Registered: Jun 2010 posted 10-08-2010 04:14 PM                     2.2 has worked worked well enough when our client wants to view non reference slide shows or a power point from their laptop's DVI out. As you stated, because of all the variables within laptops graphics and OS settings we always make it clear to the client that the projected image may not be an exact or correct representation of their content, especially with regards to the black levels. (btw, 1st post YAY!)  |  IP: Logged System Notices Forum Watchdog / Soup Nazi Posts: 215 Registered: Apr 2004 posted 02-20-2012 01:15 AM                 It has been 499 days since the last post.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 02-20-2012 01:15 AM                        Bump. Running HDCAM directly into a series 2 Christie via HD-SDI, using YCbCr 709 colorspace, I was happiest with the "NTSC" gamma setting. I have no idea what this really is or if it is correct, but it makes pretty pictures. Is there any reason not to do this? And what is "NTSC" gamma, anyway?  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 02-20-2012 02:54 AM                        7.5 IRE for USA and 0.0 for Japan.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-20-2012 06:30 AM                     The "correct" gamma would be 2.3 - 2.35. I'll see if I can find out what the "NTSC" gamma is. As Joe pointed out...it is probably optimized for SD video with a 7.5IRE lower reference.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 02-20-2012 08:46 AM                        quote: Joe Redifer 7.5 IRE for USA and 0.0 for Japan. How does it know where it is?  |  IP: Logged Joe Redifer You need a beating today Posts: 12859 From: Denver, Colorado Registered: May 99 posted 02-20-2012 08:55 AM                        It comes with its own GPS.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-20-2012 10:31 AM                     Ask a silly questions... It doesn't.  |  IP: Logged Alan Gouger Jedi Master Film Handler Posts: 501 From: Bradenton, FL, USA Registered: Jul 2000 posted 02-20-2012 11:22 AM                        The problem with lower gamma it visually brings out the nasty's ( banding, posturization during fade in/outs, compression artifacts ) in the source. Even if authored for 2.2 the compression used ( including Blu-Ray ) proves not big screen friendly especially if you have a bright projector. For consumers 4k display is the new buzz allowing one to sit closer. I cant see anyone wanting to sit closer to the moving squiggly artifacts, "distracting". Most of this stuff is authored with j6p in mind for a 42" plasma. Using a higher gamma can hide some this but be careful to not crush detail. I find 2.4 is a fair compromise.  |  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.