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Avid and anamorphic lenses with squeeze 1:2

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Lena Gregorian
Avid and anamorphic lenses with squeeze 1:2
on Aug 18, 2019 at 8:27:57 am

Hello everyone,

I’m assisting to an editor on a project.
The project was shot with anamorphic lens with squeeze of 1:2.
I need to understand how to work with anamorphic lenses with squeeze 1:2 on Avid,
from the stage of creating a project and importing or link to AMA.

I’ve been told after de-squeeze the resolution will be
5760x2160 (1:2.66)
And the timeline should be:
2048x858 (1:2.39)

Why the difference between the de-squeeze and timeline?
What is to know when working with anamorphic lenses?
Is there a good tutorial or a blog post you’d recommend?

Thank you
Lena


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Oliver Peters
Re: Avid and anamorphic lenses with squeeze 1:2
on Aug 18, 2019 at 12:31:41 pm

[Lena Gregorian] "Why the difference between the de-squeeze and timeline?"

The de-squeezed size is the size that the file becomes after you are change the pixel aspect ratio back to 1:1. Basically reversing the image squeeze created by the anamorphic lens. This sounds like Alexa footage with a file size of 2880 x 2160. So that means the lens is squeezing the image going through the lens by 2x.

The timeline setting is a standard size used for 2K scope projects. This means that your footage will be resized and somewhat cropped on the timeline.

- Oliver

Oliver Peters - oliverpeters.com


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Lena Gregorian
Re: Avid and anamorphic lenses with squeeze 1:2
on Aug 25, 2019 at 12:45:08 pm

Hello Oliver,

I'm now looking at the footage and the files from the camera are 2994x2176 (2.706), at 24 FPS, ProRes(4444) - This is shown to me by the program "Media Info".

The photographer told me the shot is: 5760x2160 (1:2.66), after de-squeeze.
However the footage is not 5760x2160 (1:2.66), and my guess is, because it's still squeezed, and when I desqueeze the footage it will be 5760x2160 (1:2.66).

I've used the timeline settings: 2k dci 2048X858 (1:2.39) - there's a preset in Avid.

In "Source Setting" I look at frame flex, image size and there's no format: 5760x2160 (1:2.66)

It's either 4K or 8K, but not 5K.

So I wonder how should I get that exact format? Can I manually add it?

Also this aspect ration of (1:2.66) - does not exsist. Can I add it manually?

Thank you,
Lena


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Oliver Peters
Re: Avid and anamorphic lenses with squeeze 1:2
on Aug 25, 2019 at 7:07:34 pm
Last Edited By Oliver Peters on Aug 25, 2019 at 7:25:34 pm

I think you mean 2944 x 2160, which would be correct for Alexa. (See image from Switch's info panel from a similar media file that I have.)



So if you are in a 2K DCI formatted project, Frameflex in Source settings should take care of you. Here's a settings grab from one of these media files. In other words, changing all of the source settings for Frameflex will probably hurt, rather than help. The automatics seem to be correct.



It will edit to the timeline as you see it in the lower image in that pane. However, because of the differences between size and aperture, and 2.66 versus 2.39/2.40, you will still have to zoom in slightly (timeline effects control, not source settings) to make sure your image sides go all the way to the edge of the sequence raster. Does that make it clearer?

- Oliver

Oliver Peters - oliverpeters.com


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Lena Gregorian
Re: Avid and anamorphic lenses with squeeze 1:2
on Aug 25, 2019 at 8:05:04 pm

Hello Oliver,

This is how I've adjusted the frame in frameFlex:



I've entered the values of 5760X2160 in the Image Size
The image aspect ratio is 2.67:1
in FrameFlex: the image aspect ration is also: 2.67:1

and in reformat I chose "letter box/ pillar box"
Should I stretch further to the sides?

Thank you.


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Oliver Peters
Re: Avid and anamorphic lenses with squeeze 1:2
on Aug 25, 2019 at 8:51:35 pm

If it looks correct, then that should work, too. But I think you'll still need to uniformly zoom in slightly.

- Oliver

Oliver Peters - oliverpeters.com


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Lena Gregorian
Re: Avid and anamorphic lenses with squeeze 1:2
on Aug 30, 2019 at 7:26:05 am

What is Uniform Zoom?
Is that something you do in FrameFlex?
I see there are black adges on the sides, but this is the resolution the photographer assigned.
If I zoom then the information on top and buttom of the frame will be cropped.
Should the frame be further streched?

Thank you


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