If you have a Sony high definition television, the set automatically displays the highest resolution image possible. If the set produces 1080p, and you are using components capable of 1080p -- a cable receiver or Blu-ray player -- you will see 1080p resolution. However, some hardware may be sending a 720p image signal, which you must change manually.
Power on both the Sony TV and the connected hardware. Press the "Menu" button on the connected hardware's remote control.
Choose "Options" (do note the wording may vary, depending on the hardware you are using), then select "Aspect Ratio."
Select "1080p" and press "OK." The image resolution now adjusts on the Sony television to display the 1080p format.