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

» Film-Tech Forum ARCHIVE   » Operations   » Digital Cinema Forum   » Picture size issue with D-Cinema (Page 1)

This topic comprises 2 pages: 1  2

Author Topic: Picture size issue with D-Cinema Thomas Pitt Master Film Handler Posts: 266 From: Leeds, West Yorkshire, UK Registered: May 2007 posted 02-10-2010 06:31 PM                     My local theater, the VUE Leeds Light, has recently installed RealD 3D systems in two of their screens. In both of these installations, the Victoria 5 has been removed and replaced with a Christie Digital projector and Real D polarizer. In both of these screens, the picture seems too small when operating in 'flat' mode - there's a noticeable unprojected area on the left, top and right of the image. When it switches over to 'scope' mode, the top masking drops, some lenses on the projector change, and the image now fills the scope area of the screen - including the parts that were unprojected before! I'm not a D-Cinema installation technician, but I do wonder why this is happening. Could it have something to do with the top masking? (i.e. the image has to be off-center to allow the scope image to be full) Oddly, the D-Cinema (2D only) projector in a third screen doesn't have this problem with scope format films!  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-10-2010 07:12 PM                     It is all in the lenses. Christie was a late commer in the motorized lens game. Hopefully, they have a suitable lens that covers both flat and scope ratios...on the 1.2" lenses it is possible to be on the edge of a range...the .98" ones have more overlap. Though there are many 1.2" lenses to try and cover the "between sizes." You then have to contend with the fact that flat does not fill the width of the imager....1998 rather than 2048. Scope does not fill height 857 instead of 1080. The other potential issue is again vintage related...if the projectors do not support full-frame triple flash...then one almost always needs another lens (shorter) to fill the same size screen since the EFIB board (can't do full-frame triple flash) do not, indeed, fill the regular image The EFIB boards are based on a 1920 maximum width (rather than the imager's 2048 or the normal flat of 1998). So a flat Real-D image will be 1920x1038 and scope will be 1920x804. Steve  |  IP: Logged Elise Brandt Expert Film Handler Posts: 160 From: Kuusankoski, FIN/ Kouvola, Finland Registered: Dec 2009 posted 02-11-2010 03:05 AM                     You mean to say there isn't an option for adjusting the lense settings in that projector? I don't know squat about any other than our projector but to me it makes no sense at all not to be able to adjust the settings, which would solve the problem in this case. Or have I misunderstood something here?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-11-2010 05:30 AM                     It would be a manual zoom...you physically move the zoom ring. But to have a single lens that can zoom between FLAT and SCOPE for both the 2D 2048 maximum width and the 3D 1920 maximum width is unlikely. Again, if it is a manual system...they probably don't worry about the previews and just leave set for scope. By the end of the series 1 projectors (2009) all new projectors had motorized zoom lenses. All of the Christie projectors had FFIB boards for full-frame triple flash. Steve  |  IP: Logged Thomas Pitt Master Film Handler Posts: 266 From: Leeds, West Yorkshire, UK Registered: May 2007 posted 02-13-2010 11:07 AM                     There is no border on the bottom of the image - it's matched up perfectly with the masking. There IS a border on the other three edges of the image though. If you were to increase the picture size by zooming the lens, the bottom of the image would be on the masking. I've seen 3D movies in these screens that are flat, and yes, the image does remain small and off-center. It's probably got nothing to do with the different sizes of 2D and 3D images, since the 2D preshow commercials and trailers are also affected by the small picture size. If it is something to do with the top-only masking, surely there should be some way of adjusting the scope lens so that it projects a little bit downward (like with 35mm turrets). The flat lens could then be aligned and zoomed to fill the screen properly.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-13-2010 11:43 AM                     Actually...when running a mixed 2D/3D show (previews in 2D 3D feature)...the system is always in 3D mode...or you would have big brightness variances plus other complications. The method of shifting an image varies too. There is physical lens shift and there is also "positioning" shift on the DMD itself. Those with Top only masking will often position shift the image down on the DMD for scope since it only has 804 on an EFIB or 857 on an FFIB thus there is room to move the image down. If the scope feature looks right...I can almost guarantee you are seeing an artifact of how they centered the scope image for the feature and those not in the same format will fall where they fall on the screen. Again, with the current stuff (FFIB and motorized zooms/shifts)...this could be avoided but that was NOT always the case. BTW...zoom is only symmetrical when the lens is centered on the imager...once it is shifted it will zoom about the LENS' virtual center, not the imager center. Steve  |  IP: Logged Brendan Penny Expert Film Handler Posts: 121 From: Bundoora, Australia Registered: Dec 2008 posted 02-13-2010 05:58 PM                     There are HEAPS of Christie's here in Australia that have been installed with manual zoom lenses. Why o why anyone would buy a projector that is unable to automatically change formats automatically is beyond me. Its like buying a 35mm with a single lens turret! Anyway, the result is the same as you describe down here. Projector often fills the screen for feature o.k but pre-show is ran somewhere/anywhere on the screen often not filling it entirely. Mainly due to the projectionist not manually adjusting the zoom to suit the content aspect. Generally they set the lens to suit the feature aspect and just leave it. I would say the Exhibitor either was on a tight budget or picked the cheapest quote without doing their homework. So beware if you are buying a projector. Remember to ask if the lens is motorized!!  |  IP: Logged Demetris Thoupis Phenomenal Film Handler Posts: 1240 From: Aradippou, Larnaca, Cyprus Registered: Apr 2001 posted 02-14-2010 01:54 AM                     When having common width for both flat and scope a manual lens is money saving since you do not need to zoom almost at all for changing from flat to scope. The case is not the same if you have common heigh which usually needs scope to zoom more than the flat. Demetris  |  IP: Logged Brendan Penny Expert Film Handler Posts: 121 From: Bundoora, Australia Registered: Dec 2008 posted 02-15-2010 03:26 AM                     Most screens over here now are unfortunately constant width and there in lies the problem!! Bet you 'almost all' exhibitors don't bother moving the lens "almost at all" and invent a new aspect ratio!! Lets call it approxyvision! I can only think of a handful of scenarios where you would not need a motorized lens. For a multiplex, there is no money saving way about it really. You either pay someone to stand there and adjust the lens manually or buy a motorized lens! Or...not bother at all and go with approxyvision.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-15-2010 05:50 AM                     Just to be clear....until 2009...on a Christie projector...motorized lenses WAS NOT AN OPTION. Christie has since come up with a novel retrofit for their projectors. The existing lenses get snap-on rings to handle focus/zoom anthe lens mount gets changed to a motorized one. While Christie was first in all FFIB boards, first in all HDCP compliant projectors, seemingly the only one that offers all projectors with motorized lens mounts (anamorphic or WCL) and has stuck to the 1.2" imager for all but their smallest projector...they were last in motorized lenses. NEC was first in motorized lenses, then Barco, then Christie. Whether you all want to believe it or not...this is STILL an emerging technology. You are going to see advances like this as the needs of the industry change. 3D was not high on the list until relatively recently...hence the whole EFIB/FFIB thing. Steve  |  IP: Logged Brendan Penny Expert Film Handler Posts: 121 From: Bundoora, Australia Registered: Dec 2008 posted 02-15-2010 04:59 PM                     I did not know that. So is it the MALM that is the retrofit add-on that you speak of?? How much does it cost, ballpark?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-15-2010 08:44 PM                     The MALM is for the Anamorphic or WCL lenses...not the lens shift or motorized zoom/focus. Steve  |  IP: Logged Sonja O'Reilly Film Handler Posts: 18 From: San Diego County, CA, USA Registered: Jun 2002 posted 02-17-2010 01:14 PM                     Thomas, my old theatre had the same problem with our Christie and our tech told me to manually turn the knob (that's below the lens) to move the lens upwards (he said to never move the side-to-side without his permission, by the way). This took care of the image running over the bottom masking. Then you manually zoom the lens. We'd have to adjust it a bit to make it look good. Edit: It's not really aproxyvision that way, as we can't change the aspect ratio, just the size of it.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 02-19-2010 01:45 AM                     quote: Thomas Pitt There is no border on the bottom of the image - it's matched up perfectly with the masking. There IS a border on the other three edges of the image though. If you were to increase the picture size by zooming the lens, the bottom of the image would be on the masking. Your installation techs suck. They should have never left the building until this and your other issue was done right, and they are tremendously easy fixes too.  |  IP: Logged Michael Brown Phenomenal Film Handler Posts: 1522 From: Bradford, England Registered: May 2001 posted 03-05-2010 09:42 PM                     The studio's have pushed the 3-D phemomenon really agressively over the last few months, so cinemas have been forced to take it on. If you haven't got 3D you are old news, you can't show the latest nunber one blockbuster, the way that it's been marketed. Simple as. So the head office of the multiplex roles out 3D installs to as many sites as it can. If they don't, all the customers will go some place else. So you have all these digital installs done in a rush, the quality could be better, but do you really have more time?  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

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.