Instructions
Access the Settings tab on the Xross Media Bar.
Scroll down and select "Display Settings."
Press X to select the first option, "Video Output Settings."
Select the video cable connection you used to connect the PS3 to your television. Each setup is displayed by a graphic of the connector and its plug on the console.
Select "Custom." Uncheck all of the display resolution boxes that are not supported by your television. If you have an incorrect display resolution selected, the console may conform the display to a square that cuts off part of the picture during Blu-ray playback. Selecting the correct display will show the Blu-ray in its natural wide screen format.