I don't know how to change the screen size when playing Blu-Ray's on my PS3!?

I was expecting to settle down, and relax while watching some of my favorite movies on Blu-Ray, but the screen is way to small. I have an Insignia 32'; (720p) with the HDMI cable for the PS3. The screen has fat lines surrounding the entire screen whenever I put Blu-ray's in there. It's like the quality is really bad when I play Harry Potter and The Sorcerer's Stone, it's like DVD quality. It also puts the small screen on when I put Horton Hears a Who in (which is a relatively new Blu-Ray disc). Can someone please tell me how to adjust the screen. And can you tell me in Lamens terms, because I'm not too smart with the technical junk. THANKSI don't know how to change the screen size when playing Blu-Ray's on my PS3!?
EDIT-Try the adjustments on the PS3 first. I think that might solve your problem.



If the black bars are surrounding the entire picture instead of just the top and bottom, it leads me to think the TV may be the culprit. Try looking through the TV menus to see if there is a picture adjust somewhere. You should be able to do this while you've got a Blu-ray on the screen, paused so you can get instant results.



EDIT- Go into the PS3 SETTINGS, scroll down to VIDEO SETTINGS, then go to BD/DVD UPSCALER and set this to NORMAL. I remember if this is set to double this was happening to my screen on DVDs. I just turned on the PS3 and checked and it looks like it effects Blu-rays too.I don't know how to change the screen size when playing Blu-Ray's on my PS3!?
Noah is on the right track. Find the menu option that refers to Video, and change the aspect ratio.



There will be two or three different aspect ratios to choose from, depending on the make and type of TV you own.



As Noah said, play the Blue Ray while changing these options, and learn the one that looks the best.