DCP Aspect ratio trouble with 2.4:1

Anything and everything to do with DCP-o-matic.
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neato_orpheus
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Joined: Fri Jul 12, 2019 11:56 pm

DCP Aspect ratio trouble with 2.4:1

Post by neato_orpheus »

I shot my film on a Blackmagic mini ursa 4.6K at 2.4:1 aspect ratio. The picture resolution is 4608x1920.

The first time I ran the DCP I did it in FULL FRAME and that left uneven black bars when we put it in the projector to test.
The tech said they have lenses for SCOPE and FLAT.
So I am doing a DCP in SCOPE right now but when I did it said I would need to crop or else it would be piller boxed.

I have no idea how to crop it. What dimensions do I put it so it will play like it does in the regular playback?

Sorry if this sounds needy I just have the premier on thursday and I gotta figure this out
carl
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Re: DCP Aspect ratio trouble with 2.4:1

Post by carl »

Your image is very close to the Scope ratio, and will need scaling anyway, so I would just select "scale to" scope and "DCP container" scope and that should be fine. You could make a 4K DCP if you wanted.
neato_orpheus
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Joined: Fri Jul 12, 2019 11:56 pm

Re: DCP Aspect ratio trouble with 2.4:1

Post by neato_orpheus »

I didn't see a "scale to scope" option in the program.
Should I stop the unscaled one I am doing now and start over?
neato_orpheus
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Joined: Fri Jul 12, 2019 11:56 pm

Re: DCP Aspect ratio trouble with 2.4:1

Post by neato_orpheus »

I didnt see a scale to scope option in the program.

Would you advise that I stop the unscaled scope DCP I am running and do the scale to scope? Where would I find it?
carl
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Re: DCP Aspect ratio trouble with 2.4:1

Post by carl »

It might already be set up right as DCP-o-matic does have a guess.

In the video tab.
Carsten
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Re: DCP Aspect ratio trouble with 2.4:1

Post by Carsten »

'4608x1920'

Is that active pixel - do you want all the 1920pixel height to be visible?

4608/1920 would translate into a 4k/2.40:1 frame of 4096/1716 - perfect (well...) DCI scope.

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@Carl - can you explain why DCP-o-matic does not create 2048/853 or 4096/1706 with slim letterbox bars? Will make no real difference, and in general, I would probably prefer the proper container being filled anyway and ignore the very slight vertical stretch, but, out of curiosity - is there a 'snap' or rounding feature that causes this?
Last edited by Carsten on Sun Jul 21, 2019 9:30 pm, edited 3 times in total.
Carsten
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Location: Germany

Re: DCP Aspect ratio trouble with 2.4:1

Post by Carsten »

Oh - and @neato - it is probable that you chose 'simple' interface during installation without understanding what it means - so you can not see the ScaleToScope option. No problem, in this case DCP-o-matic will choose the right scaling automatically from your source file dimensions (which is scope). However, it will not choose the best container automatically (it probably should, at least in simple mode...).

Goto preferences and choose full interface complexity - then you will see the full set of options. But again, this is not necessary to create a proper 4k scope DCP from your content - just set container type to DCI scope and 4k under the DCP tab as shown above, and it will create the right DCP even in simple interface mode.
Your installation may also still use the conservative 100MBit/s datarate default though - you can adjust this up to 230-240MBit/s for a 4k feature - again, only after you have switched to full interface complexity.

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neato_orpheus
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Joined: Fri Jul 12, 2019 11:56 pm

Re: DCP Aspect ratio trouble with 2.4:1

Post by neato_orpheus »

This makes sense! I was wondering why i wasn't seeing more options.

But yes I am encoding one now with 4k scope. I just how the bit thing you are talking about wont have too much of an effect.

Fingers crossed. I don't think Ill have time for another one
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