I am trying to make a scene with camera math (using Blender v2.91.0). When I test-rendered the scene, it took all day to render, even though it is a very simple scene so far (my computer is not very fast). So I would very much like to reduce the render-resolution to speed the rendering.
But when I set set the Resolution to 50% (or something else smaller then 100%) it only scales the rendered elements down, the background image it put in full size cropped (It correct in the viewport and when I render in 100% resolution).
I have tried all I can think of, to correct this: "Frame Method: Stretch", "Frame Method: Fit", "Proxy Render Size 50%"
And I have spend a long time trying to Google solution, but with no luck.
I guess, it is a simple thing, I have missed, and I hope someone here can help me.