Alexa 2x Anamorphic - to squeeze down or stretch out?

[Mark Kenfield]

Hi guys,

 

Just wondering if there's any particular standard that people tend to go with for a 2x anamorphic workflow with ProRes from the Alexa - are you generally squeezing the 4:3 2048x1556 image down and cropping the sides for a 2k 2.39:1 image (2048x858)?

 

Or stretching the picture horizontally (to get a 4k 4096x1556 Cinemascope image) and then cropping the sides down to a 2.39:1 3719x1556 picture? (or 5162x2160 when recording 2.8k Arriraw)

 

I'm wondering what people's go-to recipes are.

 

Cheers,

Mark

[Phil Rhodes]

Depends what your deliverable is, I guess.

 

When I recently shot some 1.3:1 stuff on an Ursa I letterboxed it into a 1080p frame, but it's only for Vimeo.

 

Does the Alexa not support marking the pixel aspect ratio in the file? Even if it doesn't, which would astonish me but I must admit I don't know, you could remux it with a software tool and mark it as 2:1, then you could work on it on a flat timeline without much care as to the actual resolution.

 

P

[Mark Kenfield]

Thanks Phil, it's pretty simple and painless to do it either way in Resolve (you just tell it the clips are cinemascope in the clip attributes) and then set the output scaling to clip off the sides of the 2.67:1 image to just give you 2.39:1 instead.

 

I can see some distinct advantages to working with 3719x1556 (which could be downsampled to a nice sharp 2k afterwards, or kept in near-UHD for a broader range of options. I guess mostly I'm just wondering whether anyone's likely to have issues with, or complain about a non-standard resolution like 3719x1556.