Setting Skybox texture size to display exactly once

I have a scene in which I want to display my webcam video in the background. I added a skybox in the render settings and each frame I update it using:

RenderSettings.skybox.SetTexture(“_BackTex”, usersImageTex);

However, only part of the texture is displayed, or if I increase the camera field of view then it is being tiled. (The camera aspect ratio seems to be different from the texture aspect ratio.) How do I adjust it so that it shows the complete texture? I’ve tried using RenderSettings.skybox.SetTextureScale but it doesn’t seem to have any effect.

I’m working with a static camera here, so it doesn’t have to move.

This post has a nice step by step guide: