To Match a Real-World Camera Frame Proportion

1. Choose Rendering Render Setup.

   The Render Setup dialog opens.

2. In the Output Size group, click the arrow to display the list of real world output sizes.
3. Select the type you want (both film and video output sizes are available).
4. Click or right-click the Camera viewport label, and turn on Show Safe Frames.

   The Safe Frame proportions will match those of the selected output size.