Hi
well its a bit scattered, as there is no real device aspect ratio in clarisse.
So basics first:
The device aspect ration is usually based on
"resolution" x "pixel aspect ratio"
If you want a 2:35 aspect ratio and you have square pixel ratio then simply change the resolution settings to something like
3840x1634
Now there are a few parameters that affect a setup so that it works as expected, and ill explain which ones are relevant:
- The camera and the fit mode
- The image resolution and display ratio
- The image layer pixel aspect ratio
1. Check the camera aperture, as it defines the aspect from the camera. Here i have imported an alembic camera with a square aperture (36 mm)
Also keep notice of the fit mode, by default it is horizontal
So this will render with 2.35 because the camera refers to the horizontal info only and fills in the vertical part based on my resolution ratio.
2. As you can see above the 2:35 ratio works (contrary to my square camera aperture) and i also have square pixels. If that would be an anamorphic lens, you have to set the camera remap type to remap, which will squeeze the image ratio to the camera aperture, and would stretch my render as my resolution is not square.
Display Ratio will actually show the render nonsquare.
3. The image layer also got its own pixel aspect ratio, which works if the camera fitmode is set to filled.

- aspectLayer.jpg (15.83 KiB) Viewed 93 times
Overall a bit complex but really rarely is it required to fiddle with all settings, unless anamorphic renders are needed.
Hope this helps more than confusing

Cheers
Kai