In the UnrealMatch3 demo game there is a camera called Match3camera. When I click the camera it shows a small window displaying what the camera sees. The area it displays in the preview window is much smaller than what the game should be displaying. However, when the game is tested the games displays without issue. How is this achieved?
The Camera preview in the bottom only shows this widescreen aspect ratio. When checking the camera or testing the game you will want to hit the Play button down arrow and select New Editor Window. This will pop up a window showing the correct camera aspect ratio that is needed. This screen size property was set in the Edit > Editor Preferences > Play > Play in New Window size.