Film-Tech Forum ARCHIVE: DCP Named "C"

This is topic DCP Named "C" in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Bradley J Sime (Member # 9423) on 04-22-2016, 11:36 AM:

Is this flat or scope?

Posted by Mike Blakesley (Member # 26) on 04-22-2016, 11:45 AM:

I think C stands for Common, meaning you can play it either way.

Posted by Bradley J Sime (Member # 9423) on 04-22-2016, 11:50 AM:

Okay. Thanks. Well, the pixel lay out is closer to that of Scope, so I guess I'll use that? Why the hell does "C" exist?

Posted by Mike Blakesley (Member # 26) on 04-22-2016, 11:52 AM:

Like I said...so you can play it either way without fear of cutting off the picture.

We have a couple of snipes that are in "C" format.

Posted by Dan Puma (Member # 9324) on 04-22-2016, 11:54 AM:

Full Container. It's 1.90. Will be letterboxed in flat. But Steve, et al can tell you a lot more than I can.

Posted by Tim Linehan (Member # 9429) on 04-22-2016, 12:28 PM:

It's full container 2048 x 1080 - *should* be flat.

I've had projects come in as C which were various aspects, i.e., 1:33, 16:9, or 2.39 pillar boxed. I was told that certain DCP authoring programs default to the C, inexplicably sometimes.

Look at it and see. It's probably 1.85, slightly letterboxed.

Posted by Bradley J Sime (Member # 9423) on 04-22-2016, 01:55 PM:

Thanks guys. I went ahead and made a new 2048x1080 No Crop Channel on my projector. Easiest way. I still don't really see the purpose of the crazy "C" naming convention, but whatever.

Posted by Carsten Kurz (Member # 5396) on 04-22-2016, 02:27 PM:

IF they chose that container type intentionally, a simple 'C' will mean a full container with 2048*1080 active pixels.

Any content letterboxed or pillarboxed within a C container should have it's aspect ratio added as a number.

See: http://isdcf.com/dcnc/

See also:

http://isdcf.com/dcnc/home/appendix-7-projector-aspect-ratio.html

And:

---
ISDCF recommended practice that for aspect ratios under 1.85 (such as academy aperture 1.33) pillar box in a flat package. For aspect ratio from 1.85 to 2.30 letter box in a flat package. For aspect ratios above 2.30 letter box in a scope package. The suggestion is to inform the theaters of the actual aspect ratio of the feature and not request/require masking - but if someone wanted to - great! BUT you must not mess up the trailers - so the masking would need to be automated before the feature.
---

- Carsten

Posted by Leo Enticknap (Member # 534) on 04-22-2016, 03:07 PM:

quote: Carsten Kurz
ISDCF recommended practice that for aspect ratios under 1.85 (such as academy aperture 1.33) pillar box in a flat package. For aspect ratio from 1.85 to 2.30 letter box in a flat package. For aspect ratios above 2.30 letter box in a scope package.

Interesting - all the Todd-AO ratio (2.20:1) studio DCPs I've had (e.g. Oklahoma and Hello Dolly) have been pillarboxed in scope (S-220); presumably because if they were letterboxed in flat, most screens with only two projector presets and vertical masking would just show them flat with a big letterbox if they were F-220.

I'm not sure that this is the best recommended practice, given the reality of most of the digital screens out there.

Posted by Carsten Kurz (Member # 5396) on 04-22-2016, 03:31 PM:

Tomorrowland and Jurassic World had been letterboxed in Flat containers (F-20, F-220).

That ISDCF recommendation is a fairly recent one, and it is not the law.

- Carsten

Posted by Mike Babb (Member # 1379) on 04-22-2016, 03:40 PM:

In my experience outside of most major studio releases, C means nothing, and often F means nothing and S means nothing. It's very common to have mismarked titles, or titles with no information at film festivals. But C should be container, 2048 x 1080, it just rarely is.

Posted by Bradley J Sime (Member # 9423) on 04-22-2016, 04:14 PM:

I dunno, when I played the C film with a Flat (1920x1080) it looked wack. It looked a little wack using the scope lens, too. The only way I could find to get it where I wanted it was to create a new channel with the dimensions given for a full container.

Posted by Marco Giustini (Member # 4544) on 04-22-2016, 05:28 PM:

Full container is not Flat. It's full container! You should have a specific macro on your projector - not that anybody has it.

IF the content is actually full container (choose a full container PCF and disable masking to check) THEN you will need a proper macro.

Alternatively if you can't be bothered you can chop off the extra picture on the sides.

Posted by Leo Enticknap (Member # 534) on 04-22-2016, 05:51 PM:

quote: Bradley J Sime
I dunno, when I played the C film with a Flat (1920x1080) it looked wack.

Possibly because flat (F) is 1998x1080, not 1920x1080. 1920x1080 is F-178.

Posted by Bradley J Sime (Member # 9423) on 04-22-2016, 05:55 PM:

Yeah I made a macro for it.

*Oh yeah I meant 1998x1080

Posted by Steve Guttag (Member # 268) on 04-23-2016, 08:28 AM:

I won't rehash the "C" meaning that other have. But the usefulness of full container is there. For instance, one can create policy CPLs (Fire Exits and such) in a full container so they work either way...just make sure your text is constrained to 1998 x 858 (for 2K) and let the background (whatever it may be) be cropped as the feature format so needs. You only have one version then. Those that have the original DLP CPL have "C" versions despite someone trying to make flat and scope names for them, the SMS player (and projector) know it is a 1.90 ratio CPL, it doesn't go by the name but by the data in the CPL.

As others have noted, some ratios are better handled by "C" than "F" or "S". To Leo's comments, Lawrence of Arabia is F-220, as I recall and if not, I know there are some because, in their minds, you get more pixels by using the Flat container. But in reality , those SHOULD be C-220 to get maximum pixels representing an image of higher resolution than the 4K system showing it. 4096x1862 beats 3774x1716 (S Container) or 3996x1816 (F container). I claim that if you release such a classic title in "C-220" that if people play it in Scope, they will merely crop slightly ...just like they did when they did print downs to 35mm scope from these titles. And, honestly, if you are going to be in the business of showing classic titles of 70mm features, then create the format for it. Regardless, unless you have masking stops for it, it isn't going to fit your screen just right since the ratio isn't flat or scope.

Posted by Leo Enticknap (Member # 534) on 04-23-2016, 01:07 PM:

The Larry DCP we've always had has been in an "S" container:

quote: Steve Guttag
and if not, I know there are some because, in their minds, you get more pixels by using the Flat container.

The number of pixels is not the only factor you have to take account, of, sadly. If you've got a typical multiplex screen in which only the vertical, side masking curtains are adjustable, and where the projectionists on site do not have the ability and/or authorization to create bespoke lens and screen files in their projectors, then a F-220 container means playing the movie letterboxed within 1.85. S-220 gives you pillarboxed within 2.39, which, although you're watching fewer pixels at a greater magnification, does at least mean a smaller area of black screen.

It's the same syndrome as the occasional re-release on 35mm of an iconic 1.37 title being printed pillarboxed within a 1.85 matte. Image quality wise it was effectively 16mm, but distributors had to face the reality that theaters weren't going to invest in 1.37 plates and lenses, and take the risk of minimum wage operators trying to swap and align them in and out of turrets, for one show every couple of years.

Posted by Steve Guttag (Member # 268) on 04-23-2016, 03:55 PM:

Which is why "C-220" would be reasonably safe. They would play it scope and it would work on those that don't have a "C" format.