4K DCI and 2K DCI (1.90:1)

[Maurice Morales]

Hello,

When would be a use to film in 4K DCI  or 2K DCI (1.90:1)?

I apologies if this seems like a obvious answer but I have found a obvious answer and thought It’d be best to ask experienced Camera Crew.

 

Thank you for your time.

[David Mullen ASC]

I guess a Digital IMAX screening might use a 4K 1.89 image.

[Phil Connolly]

2.39:1 scope is the same width as DCI 2k of 4K. So if your framing for 2.39:1 you'd typically shoot in a 1.89:1 mode. The extra room at the top and bottom of the recorded frame is useful for reframing, hiding tracking markers, spotting the boom and giving you flexibility to make a pan and scan 16:9

It's rare to make a 1.89:1 deliverable, but it's a good ratio to shoot in when you crop to other aspect ratios. The point of 1.89:1 is that its in between 2.39:1 and 1.85:1. It cinema cameras for instance had a 2.39:1 shaped sensor, you'd need a massive crop to get to 16:9.

Digital cinema projectors have the same shape 1.89:1 sensors - so crop at either the sides or the top and bottom for different aspect ratios

[David Mullen ASC]

In DCPs, 2.39 uses max width and 1.85 uses max height.

[Maurice Morales]

Thank you David and Phil. 

I was curious of the use case for this aspect ratio. I mostly work on 1:78:1 deliverables and mostly web content. I'm just a curious cat.