To adjust the image size on your TV, navigate to: Home > left directional key > Settings > All Settings > Picture > Picture Size Settings. From there, you can select options like Fit to Screen, Zoom and Position, or choose a Picture Size such as 16:9 Standard, Custom, or 4:3. Please keep in mind that available size options may vary depending on the input signal and the type of content you're viewing.
~ Samsung Specialist