Recommendations on multi aspect ratio DCP

[Opacity3486]

Hi all, it's my first time making a DCP for theater projection. I'm wondering about best practices for my unique situation.

My short film starts in 1.37, and ends in 2:1. The overall project file is 16:9 (4K), and i've added black bars within that container to create the correct aspect ratios.

The way I see it, I have two options for creating a 4K DCP (1.85):

Option 1) Center my 4k 16:9 export within the 4k 1.85 DCP. Easy peasy. The 1.37 part of the film is pillarboxed as expected. No problem. But the ending (which is 2:1) is letterboxed AND pillarboxed when it doesn’t really need to be. The advantage here is that the 4k video is presented in its native resolution.

Option 2) Export my project as 4k 1.85:1 so it fills the entire DCP. The 1.37 bit will be pillarboxed the same as in option 1. The advantage here is that the 2:1 section will only be letterboxed.

I think I prefer option 1, as it doesn't require me to blow up the 2:1 section to fit the 1.85 width, which I worry will degrade quality. But is option 1, for lack of a better term... weird? Will this look odd in the theater, with the last 5 mins of the film floating inside a pillarbox/letterbox combo? Or is this pretty standard?

That's the essence of my question. Is option 1 weird / offputting / strange looking in a theater? Sadly I don't have a theater to try this out in, hence why I'm asking here

I attached a diagram of the two options for you visual thinkers. Any advice is much appreciated!

Frame 2.png

[IoannisSyrogiannis]

The most of the difference will be on whether the theater has a preset for 2:1 or not. There are many that don't. So, if you don't know, assume they don't.
If they have, what I would do, is have the 2:1 as in Option 2 and letterbox the 1.37:1 to fit the height of 2:1. The preset will eliminate the letterboxing, the same preset will be used.
If they don't, I would go for Option 2 (again). Either way, it makes no sense to switch between narrow and wide and not to take advantage of wide, but narrow it from 1998 (O.K. 3996) to 1920 (right, 3840). It makes no sense to me on cinema screens and it makes no sense on TV screens.
To be honest and share my personal opinion that I don't expect anyone to adopt, if I was to give the feeling of change, that I would definitely not use more than once in a full feature and probably from narrow to wide, I would go from 1.37 to 1.85:1 or from 1.37 to 16:9 to fit a TV screen. What on almost all screens is not wider but shorter (2:1), doesn't provide the effect, just distracts.
While, if I was on 4K and wanted a more wide image, I wouldn't mind going between 1.37:1 to 2:1, or 2.35:1, or 2.39:1 within the frame of 2.39:1.
In order not to give that "full-height" to "faux-wide" confusion, I (need to underline that it's my personal opinion) would prefer to trim the edges of my 2:1 material to 1.85:1.

Besides that, let's call it what it is. If you are asking about best practices, you should also consider changing the project from 16:9 to 1.85:1 (or whatever you want it to be on the cinema screen).

If you want some reassurance, the difference on the vertical axis between what you demonstrate as 2:1 is not big. In a dark cinema room, it could even not be noticeable.

[Opacity3486]

Thanks a ton for this comprehensive answer!

If I'm understanding correctly...

• Option 1 wouldn't be so bad, especially in theaters where there's a preset for 2:1.

• Option 2 is definitely preferable to option 1, since it's more flexible and will look better in more theaters.

• In your opinion, the best thing (let's call it option 3) would be to make the 2:1 section of the film 1.85:1, making this whole thing a non-issue.

Is that the gist of it? If so, that makes total sense and I'll be weighing these options. Thanks again.