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Author Topic: 2.20 DCPs Lincoln Spector Film Handler Posts: 46 From: Albany, CA, USA Registered: Mar 2012 posted 05-20-2014 02:13 PM                        Hi, folks. I know you've covered this before, but I'm still confused about it and thought I'd go from scratch. Just how does one prepare a DCP of a 65mm/70mm film shot in the 2.20 aspect ratio? And how do you (or more likely, someone who doesn't really care) project it. The two obvious solutions are letterboxing within a flat transfer, or pillarboxing within a scope one. If Wikipedia's (http://en.wikipedia.org/wiki/Digital_Cinema_Package) numbers are correct, the flat approach gives you better resolution: 7,258,189 total pixels vs. 6,478,243 (assuming a 4K projector and DCP). But then, is it possible to use the full projector image--4096 x 1,862 (7,626,007). And then there's the matter of how it works in projection. If the theater is fixed-width, a flat transfer would fill the screen's width but a scope one wouldn't. With a fixed-height theater, it would be the other way around. Lincoln  |  IP: Logged Marcel Birgelen Film God Posts: 3357 From: Maastricht, Limburg, Netherlands Registered: Feb 2012 posted 05-20-2014 02:37 PM                     There are no set standards how a film is converted to a DCP. The actual creator may even decide to crop parts of the image to attain a now common aspect ratio (screw them!). Although there are the two recommended DCDM containers (1.85:1/flat and 2.39:1/scope), DCPs don't have a fixed aspect ratio by definition. According to DCI specs, the image should either fill the whole 2048/4096 pixels or the whole 1080/2160 pixels vertically, whatever fits the source aspect ratio. The image should then be centered, as such that there are the same amount of blank pixels on either side. If you fit it into a flat or scope container, you obviously choose the container that best fits your aspect ratio, fill it either horizontally or vertically and center the image accordingly. The image should be zoomed to fit the screen and the masking should be adjusted accordingly. Some limited screens also have an anamorphic lens option for scope. In that case, the image is scaled/stretched across the full height of the DMDs and stretched back into proportions by the lens.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 05-20-2014 05:00 PM                     In practice, it is a mixed bag. Some have been letterboxed (inside 1.85) and some have been pillarboxed (inside 2.39) Of the ones I have done, NONE exploited the full width of the container. They were all formatted inside "flat" or "scope." Most likely, this is because very few digital cinemas were only set up to handle 1.85 and 2.39 and, hence, a full-width 2.2 image would end up getting cropped in some way at most locations.  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 05-20-2014 05:52 PM                     Optimum would be to pick whatever uses the most pixels IMO. That would ideally be letterboxing it into the full container. Some systems may not have a full container pcf though, and it would be cropped into scope height or flat width when projected. Probably letterboxing it into 1998 width flat would be your best choice. Pillarboxing into scope would limit Y to 838 pixels. I haven't done the math but I think that would be fewer imager pixels used than pillarboxing into flat.  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 05-20-2014 06:04 PM                        At 2K resolution, the options would be: 2048x930 = 1904640 pixels (full container) 1888x858 = 1619904 pixels (scope pillarbox) 1998x908 = 1814184 pixels (flat letterbox) The full-container version is an obvious win. Cropping that to 2.39 in a venue that lacks the proper lens and screen files for 2.2 shouldn't be too bad, since that is generally how the 35mm prints of these titles are printed. That said, any theatre that shows this sort of title really should have operators who know how to create and edit lens and screen files.... The other options are just bad. The scope pillarbox would look horrible in a venue with common-width masking. The flat letterbox would look horrible in a venue with common-height masking.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 05-20-2014 06:19 PM                     Agreed. It's better to go for the max. pixels -- but what good does that do if 1% of digital screens can play that format? Of the two compromises, "letterboxed inside 1.85" would get you more pixels than "pillarboxed inside 2.39." 2K resolutions: 2.20 letterboxed inside 1.85 1998 * 908 = 1,814,184 pixels 2.20 pillarboxed inside 2.39 1888 * 858 = 1,619,904 pixels That's a difference of 194,280 pixels. Is my math correct? Is that 12% more pixels in the "flat" version? Note that if you went for a "true" 2.20 using the full container width, there is a strong likelihood that it would get played as "Scope." In which case, the top and bottom of your image would EACH be cropped by 36 pixels. Or, worse: It gets played as "Flat." In which case, it takes on a letterboxed appearance AND gets cropped by 50 pixels on each side (left/right).  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-20-2014 08:00 PM                     The only good way to handle a 2.20:1 ratio in today's world of DCPs is to make TWO versions. One is 2.20:1 within flat and the other is 2.20:1 within scope. If the theater has a common width auditorium, they run the flat version and it is what it is with letterboxing and all. If the theater has a common height auditorium, they run the scope version and the image doesn't quite reach the sides. (Note it WOULD in some cases where they don't have a full 2.40:1 ratio screen.)  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-20-2014 08:54 PM                     I think scanning it in anything other than full-container is dumb. If you want to play the classic title...then create a new lens preset to handle it...big deal...every theatre COULD play it and not spend one cent extra on equipment. You are taking something with more resolution than DCP has and are then squishing it down and defeating the purpose of going to the 65mm material when you make it fit F or S containers.  |  IP: Logged Lincoln Spector Film Handler Posts: 46 From: Albany, CA, USA Registered: Mar 2012 posted 05-20-2014 10:54 PM                        Could someone describe to this amateur what a lens preset is? My guess, from the context, is that you've got a zoom lens, and that you adjust it not by turning a knob but by typing some numbers into a computer. Am I correct? btw, as I think about it, I've come to the conclusion that full-width 2.20 is the best solution. Not only does it give you the greatest resolution, but if a theater couldn't handle it, it would come out just as regular scope. Remember that these films were shown in roadshow at 2.20, then in wide release in 2.35. The films were shot to look good in both ARs.  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 05-20-2014 11:11 PM                     The lens is controlled by four motors. One for horizontal positioning, one for vertical, a third one for zoom and the fourth is for focus. A lens preset for a particular format (flat, scope, etc) will store the motor position values for each of those parameters. When a preset is recalled, the motors are all driven to the required positions. (But the lens preset is only one part of a format macro. A "screen file" is also needed. You can think of that as a digital aperture plate. And a light sensor file should also be created, which is (basically) a way of telling the projector (for each format) how bright the lamp needs to be to hit the target luminance level.) In theory, it doesn't cost anything to create new presets and a new format macro. I create them all the time for our venue. But, I suspect many cinemas would actually need to pay for a tech to come out and create a new setting. This is because a lot of cinemas seem to be tech-less now.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 05-21-2014 05:29 AM                     Manny, The theatres that are going to cater to classic titles should and likely will be able to have presets created. Furthermore, as Lincoln stated, if formatted full container...the worst that would happen if run in "Scope" is that some of the image height would be cropped. About like it was on the original release in 35mm. There really is no excuse for this stupid sub-standard handling of DCPs of classic titles, particularly those that started in 65mm and other large aperture formats.  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 05-21-2014 06:59 AM                     I would also do two versions. It's easier for staff to decide wether to go the Flat or Scope way in their specific theatre, and you can be sure that there is a suitable lens preset and masking (if at all) in every theater this is played. As you are not familiar with these operations, typically the projection staff will identify the DCP by following the Digital Cinema Naming convention. The title will have an indicator 'F' for flat, or 'S' for Scope, and staff looks at this indicator first to program the necessary lens and mask setting. If you offer both options, they will probably make a guess based on their specific screen setup. At a constant height screen, they will naturally choose the 'S' option, while at constant width, they know the 'F' option will give the largest image. You should still put the 2.20 aspect ratio in the name after the 'F' or 'S' indicator so that educated staff knows whats in the DCP. http://digitalcinemanamingconvention.com/unabridged.asp - Carsten  |  IP: Logged Manny Knowles "What are these things and WHY are they BLUE???" Posts: 4247 From: Bloomington, IN, USA Registered: Feb 2002 posted 05-21-2014 01:55 PM                     Steve, Why do you love to pick on me? As you know, I've complained about the current handling of 70mm titles. Anyone who doubts this, or needs a refresher, can refer to my comments in the following threads: Off aspect ratio DCP's DCP Classic Transfers Good and Bad 70mm DCPs and their formatting Sound of Music DCP Formatting In anticipation of my first "restored" 70mm title, I went ahead and created a 2.20 based on full-container width. I also made special cabling and audio presets to accommodate "five across" sound. I've shown several of these DCP restorations/transfers now, and haven't yet had an opportunity to put any of these efforts to use. So, I'm not making excuses for the studios. I'm pissed off about it, but I've simmered down a bit since this first came up. (This is about the 4th or 5th thread on this subject in the past year or so.) At this point, I'm just trying to explain WHAT appears to be the common approach, and taking a guess at the probable motivation for doing it that way. That's all.  |  IP: Logged Antti Nayha Master Film Handler Posts: 268 From: Helsinki, Finland Registered: Oct 2008 posted 05-22-2014 02:57 AM                     Amazingly, we're now also getting some new films in 2.00:1 ratio - I suppose that's because of this being a common acquisition AR with RED cameras. These are commonly 2048x1024 and tagged as F or C. Most theatres by far will simply project these in flat (leaving letterbox bars visible, sometimes blank screen on all four sides), while some just violently crop them to scope. Oh well.  |  IP: Logged Lincoln Spector Film Handler Posts: 46 From: Albany, CA, USA Registered: Mar 2012 posted 05-22-2014 04:29 PM                        I think of 2.0x1 as a weird orphaned AR. Every few years, it pops up in some strange way, but doesn't stick around. Fox adopted it for their short-lived Grandeur format in 1929. In the mid-50s, both VistaVision and SuperScope tried to make it a standard. And then, of course, there's Vittorio Storaro.  |  IP: Logged

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