From what I’ve read, SFML is a 3D library and basically you render sprites, etc. as quads and show them using ortographic camera, right?
No, SFML is a 2D lib.
Maybe you are talking about the possibility to use an OpenGL context in a SFML window, allowing you to do any 3D related stuff? 
It seems that SFML doesn’t render quads or any primitive directly (it’s not recommended for years, I think), but instead pass vertices to the render target and draw vertex arrays (of course passing the mode here, quads, lines, etc ) 