Render Target 2D format not working as intended

What I need is to render a black and white depth. My Render Target’s Capture Source is Scene Depth in R, and the Texture is RTF R8.

What I’m getting is a black and white render stored in the R-channel. That means that instead of a depth map I have what is essentially a grayscale screenshot.

Am I misunderstanding how this is supposed to be working, or am I doing something wrong?