Tom asked: “Wondering why when I watch a DVD rather than a Blu-ray on my PS3, that the picture doesn’t fill the screen. I was wondering if that is the way they upscale, or if they upscale and make the picture smaller to try and improve the look of it. This is also true for some cable programming that doesn’t fill the screen”
Tom, it is absolutely being caused by the picture format. Different sources produce different picture formats. The most common are 1080p, 1080i, and 720p, although some channels carrying vintage content might only produce a 480i or 480p picture.
The issue isn’t really with the picture format being sent to your TV, it’s how your HDTV responds to it. Almost all HDTVs will have an option for picture format that lets you choose between leaving the picture as it is, using letterbox (blank space at the top and bottom), pillarbox (blank space on the left and right sides), or zooming the picture to fit the screen.
Making the picture fill your HDTV’s screen might be the best choice if you’re sitting some distance away, but not if you’re close enough to the screen you will notice that zooming up the picture results in some blurriness in the image.
Blu-ray will always be 1080p and that (unless you have a 4K HDTV with 2160p resolution) will fill the screen at its native resolution. Regular DVDs are usually 480i or 720p and if the DVD player doesn’t up-scale the picture to match the HDTV’s native resolution, then the picture format control on the TV itself will control how it looks.