The POV Camera Tool

The POV Camera Tools allows you to quickly and intuitively create Maya cameras.
It can be found in the Lighting Rendering Menu (which is on the right controller on the left side of the touchpad (HTC Vive or Oculus Rift) when in Lighting/Rendering mode.
The tool is indicated by the following icon:

See this video for a demonstration on how to use the tool.

Just look at an object and with a single dragging motion define the camera aperture.
MARUI will then create a Maya camera that has the exact film back aperture as the frame you defined in VR.
Hold down the “Shift” button on your controller to rotate the frame.
You can then go on and use the camera normally in Maya for animation and rendering.

In the tool settings of the POV Camera tool, you can set the tool to use a specific aspect ratio, for example 4:3 or 16:9.
You can access the tool settings by selecting the wrench icon in the upper right corner of the POV Camera Tool item in the Lighting/Rendering Menu:

When the aspect ratio is forced to a certain aspect ratio, a red inner rectangle will indicate the resulting view aperture of the camera.